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Claudin-18.2 (CLDN18.2) expression evaluated by immunohistochemistry is a new biomarker for gastric and gastroesophageal junction adenocarcinomas that will soon have market authorization for implementation into routine clinical practice. Despite successful testing in the setting of clinical trials, no specific practical testing guidelines have been proposed. Several preanalytical and analytical variables may interfere with adequate CLDN18.2 staining interpretation; thus, this article provides practical guidance on CLDN18.2 testing and scoring in gastric and gastroesophageal junction adenocarcinomas to identify patients who may respond to targeted therapy with monoclonal antibodies directed against CLDN18.2. Based on available data, moderate to strong (2+/3+) membrane staining in ≥75% of adenocarcinoma cells is the proposed cutoff for clinical use of monoclonal antibody anti-CLDN18.2 (zolbetuximab)., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Mismatch repair deficiency (dMMR) is a well-established characteristic of endometrial adenocarcinoma and is crucial in screening for Lynch syndrome, guiding adjuvant treatment decisions, and identifying candidates for immune checkpoint inhibitors. The traditional approach to dMMR screening involves a four-antibody panel, but a simplified two-antibody method utilizing PMS2 and MSH6 has shown promise. This study aims to compare the diagnostic performance of the simplified two-antibody method with the traditional four-antibody panel in endometrial cancer samples., Methods: We conducted a retrospective cohort study on endometrial carcinoma cases diagnosed between 2013 and 2022. We compared the diagnostic performance of the two-antibody panel with the traditional four-antibody panel in detecting dMMR. Clinical data and immunohistochemistry results were collected, and agreement between the two methods was evaluated using Cohen's kappa coefficient., Results: 304 endometrial cancer cases were included, with 27% demonstrating loss of at least one MMR protein using the four-antibody panel. The two-antibody method detected MMR deficiency in 26.6% of cases, with a high agreement rate of 98.8% between the two methods. Only one case showed discordant results, prompting further investigation., Conclusion: The simplified two-antibody MMR IHC screening approach using PMS2 and MSH6 showed high concordance with the traditional four-antibody panel. This suggests its potential as an alternative method for reflex MMR status testing in endometrial adenocarcinoma. The implementation of this approach could streamline the diagnostic process, reduce costs, and improve the detection of Lynch syndrome in affected individuals and their families. Further studies with larger cohorts and long-term follow-up are needed to validate these findings and assess the clinical implications of this approach in routine practice.

Background and Objectives : This study aimed to elucidate the diagnostic role of α-Methylacyl-CoA racemase (AMACR) immunohistochemistry in gastric dysplasia and adenocarcinoma. Materials and Methods : Immunohistochemistry for AMACR was performed on 39 gastric dysplasia and 40 gastric adenocarcinoma cases. The expression patterns of AMACR were investigated and divided into luminal and cytoplasmic expression patterns in the gastric lesions. In addition, correlations between AMACR expression and patient age, sex, and tumor size were evaluated. Results : AMACR was expressed in 26 of 39 cases of gastric dysplasia (66.7%) and 17 of 40 cases of gastric adenocarcinomas (42.5%). The AMACR expression rates in high- and low-grade dysplasia were 80.0% and 52.6%, respectively. A detailed analysis of the expression patterns revealed that the luminal expression pattern was significantly higher in low-grade dysplasia than in high-grade dysplasia and gastric adenocarcinoma ( p < 0.001). The cytoplasmic expression pattern, without luminal expression, was predominant in high-grade dysplasia and gastric adenocarcinoma. In addition, the rates of loss of expression in the overall area were 15.1 ± 23.9%, 49.0 ± 29.9%, and 59.0 ± 32.2% in low-grade dysplasia, high-grade dysplasia, and gastric adenocarcinoma, respectively. The negative rate of low-grade dysplasia was significantly lower than that of high-grade dysplasia and gastric adenocarcinoma ( p < 0.001 and p < 0.001, respectively). Conclusions : AMACR is a useful diagnostic marker for differentiating low-grade dysplasia from high-grade dysplasia and gastric adenocarcinoma. Luminal or cytoplasmic expression patterns and the extent of loss of expression are important for differentiation.

Background: Cell blocks (CBs) are widely used for biomarker analyses such as immunostaining. Although immunohistochemistry on formalin-fixed paraffin-embedded tissues is standardized, there are multiple preparation methods and fixatives for cytology. Our objective was to investigate the effect of different common fixatives on the immunoreactivity of pleural effusion CBs with metastatic lung adenocarcinomas., Methods: This prospective study included 24 malignant pleural effusions from different patients with lung adenocarcinoma. From each case, four identical CBs were fixed in 10% neutral buffered formalin, PreservCyt, CytoLyt, and CytoRich Red (only 17 of the cases), respectively. Samples containing <100 malignant cells were excluded. All CBs were stained with thyroid transcription factor 1 (TTF-1; clones 8G7G3/1 and SPT24), napsin A, claudin 4, CEA, CK7, and epithelial cell adhesion molecule (EpCAM; clones BS14, Ber-Ep4, and MOC-31). The fraction and intensity of stained cells were evaluated., Results: Of the investigated markers, a significant difference in staining proportion was seen for TTF-1 clone 8G7G3/1 and EpCAM clone MOC-31, especially with cases being negative in CytoLyt (33.3% and 83.3% positive, respectively) and PreservCyt (62.5% and 83.3%) whereas being positive in CytoRich Red (76.5% and 94.1%) and formalin (both 95.8%). A significantly weaker intensity of staining was seen for all alcohol-based fixatives compared to formalin for TTF-1 clone 8G7G3/1, napsin A, and EpCAM clone MOC-31, whereas EpCAM clone Ber-Ep4 was significantly weaker only in PreservCyt compared with formalin., Conclusions: Immunocytochemical expression and concordance with formalin-fixed CBs differ depending on the used fixative as well as the antibody and clone, warranting investigation of the reliability of each biomarker for non-formalin-fixed cytology., (© 2024 The Authors. Cancer Cytopathology published by Wiley Periodicals LLC on behalf of American Cancer Society.)

Objective: To investigate the expression of C6orf15 protein in gastric endoscopic biopsy specimens and its usage as an ancillary diagnostic biomarker in determining the grade of gastric dysplasia., Methods: We selected 102 patients with gastric endoscopic biopsy specimens from Jinling Hospital. These were divided into four groups: 22 cases of gastric mucosal benign lesions, 28 with low-grade dysplasia (LGD, intestinal-type: 21 cases，foveolar-type: 7cases), 28 with high-grade dysplasia (HGD, intestinal-type: 20 cases，foveolar-type: 8 cases), and 24 cases of gastric adenocarcinoma. We examined the expressions of C6orf15, P53, and Ki67 in 102 gastric endoscopic biopsy specimens, including 47 cases with accompanying endoscopic submucosal dissection (ESD) specimens, using immunohistochemistry., Results: In gastric HGD and gastric adenocarcinoma, the c6orf15 protein exhibits diffuse and strong cytoplasmic expression in tumor cells. Conversely, in gastric LGD and benign gastric mucosal lesions, the c6orf15 protein shows negative or faint yellow cytoplasmic staining. The expression rate of C6orf15 in high-grade gastric dysplasia (HGD, 93 %) and gastric adenocarcinoma (100 %) was significantly higher than in the gastric mucosal benign lesion group (0 %) and the low-grade dysplasia (LGD, 7 %) group (P < 0.001)., Conclusion: The detection of C6orf15 protein expression could serve as a valuable adjunctive diagnostic tool for distinguishing between gastric HGD, LGD, and benign lesions. The combined assessment of C6orf15, P53, and Ki67 expressions may be beneficial in determining the grade of gastric dysplasia and evaluating the risk of progression in gastric mucosal lesions in clinical practice., Competing Interests: Declaration of competing interest The author (s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Endoscopic dissection is the first-choice treatment for superficial pT1 colorectal adenocarcinoma (sCRC). Complementary surgery decision is influenced by histopronostic factors. Prognostic significance and reproducibility of each factor are not well established. The role of immunohistochemistry (IHC) and digital pathology in this context is unknown. Our aims were (1) to evaluate each histopronostic factor reproducibility comparing HES and IHC ± digital pathology and (2) to evaluate how the different techniques would affect indications for additional surgery. We performed a single-centre retrospective study of 98 patients treated between 2010 and 2019 in Hospices Civils de Lyon, France. We analyzed physical or digital slides of HES and keratin/desmin immunostaining of 98 sCRC dissection specimens. Three pathologists evaluate the histopronostic factors including submucosal invasion depth (SMI) measured using different recommended methods. Assessment of SMI with Ueno or JSCCR methods showed good to excellent interobserver reproducibility (IOR) (ICCs of 0.858 to 0.925) using HES staining and IHC. Assessment of budding on HES sections was poorly reproducible compared to IHC which exhibit moderate IOR (κ = 0.714). IHC increased high-grade budding detection. For lymphovascular invasion and poor differentiation, the IOR was poor (κ = 0.141, 0.196 and 0.313 respectively). IHC gave a better reproducibility for further treatment indication according to JSCCR criteria (κ = 0.763) or forthcoming European guidelines (κ = 0.659). Digital pathology was equivalent to the microscope for all analyses. Histopronostic factor reproducibility in sCRC is moderate. Immunohistochemistry may facilitate the evaluation of certain criteria and improve the reproducibility of treatment decisions., (© 2023. The Author(s).)

Background: Microsatellite instability (MSI) is a pattern of hyper mutation that occurs at microsatellite level in the genome and result due to error in the mismatch repair system. MSI is caused by defective mismatch repair (MMR) genes associated with either hyper methylation of MMR genes or BRAF mutations. Anti-MLH-1, anti-MSH-2, anti-MSH-6 and anti-PMS2 monoclonal antibodies are used for Immunohistochemical analysis., Methods: The immunohistochemical expression of MSI proteins were assessed in 72 cases of colorectal carcinoma. These were classified based on the expression of MLH1, MSH2, MSH6 and PMS2 proteins., Results: There were 57 percent of cases showing loss of at least one antibodies, and 43 percent cases showing intact expression of all antibodies (MLH1, MSH2, MSH6 and PMS2)., Conclusion: In conclusion, our study provides valuable insights into the expression of mismatch repair in colorectal adenocarcinoma through immunohistochemistry analysis conducted at our tertiary care centre. These findings hold significant clinical implications, suggesting further testing for BRAF and MLH1 Promoter Hypermethylation to confirm possibility of Lynch syndrome., Key Words: IHC, MMR, CRC.

Background: Colorectal cancer is one of the alarming health problems worldwide. Prognostic biomarkers are the key for risk stratification in patients with colon cancer and the decision to recommend adjuvant chemotherapy. It has been difficult to identify a single prognostic biomarker for colon cancer. Currently, tumor stage, tumor grade, and microsatellite instability remain the most important prognostic variables that aid in the treatment of patients with colon cancer. Some studies highlighted that CDX2 immunohistochemistry negativity is an independent prognostic factor and indicates a worse survival rate. Our aim was to study the prevalence of CDX2 biomarker expression in patients diagnosed with primary adenocarcinoma and to correlate this with the clinical profile and pathological features., Methods: Endoscopic mucosal biopsies and resection specimens of 148 patients diagnosed with colonic adenocarcinoma were analyzed. CDX2 immunohistochemistry was performed, and the result was correlated with clinicopathological features. The results were presented as mean, frequencies, and percentages. Pearson's Chi-square test was used to assess the associations between clinicopathological parameters and CDX2 immunohistochemistry negativity., Results: The prevalence of CDX2 expression by immunohistochemistry in colon cancer was found to be 92%. CDX2 biomarker negativity was found to be higher in left-sided colon cancers, poorly differentiated adenocarcinoma, mucinous carcinoma, and higher TNM stages., Conclusion: CDX2-negative tumors are often associated with several adverse prognostic variables (e.g., advanced stage, poor differentiation, and metastasis). Thus, sub-classification of colon cancer based on the CDX2 biomarker aids to separate them into prognostically relevant categories., (Copyright © 2023 Copyright: © 2023 Indian Journal of Cancer.)

Background: Prostate cancer is a common cancer in males, frequently leading to mortality. Multiple genetic factors play roles in prostate cancer pathogenesis. Demonstration of pathological pathways and customised treatment options have been possible with next-generation sequencing., Aim: In this study, we aimed to evaluate the relationships of the changes in the prostate cancer pathways genes with the pathological, immunohistochemical and the clinical parameters., Study Design: Retrospective cross-sectional study., Materials and Methods: Among the prostate needle biopsy materials investigated in Adnan Menderes University Faculty of Medicine, Department of Pathology, thirty-one cases, who had been analysed using the next-generation sequencing system, were included in this study., Results: As a result of statistical analysis, a significant relationship was found between the pathogenic mutation detected in androgen receptor and Breast Cancer Gene 2 genes and tumour volume. In all cases with a pathogenic mutation in the androgen receptor gene, a pathogenic mutation in the Protein Tyrosine Phosphatase and Tensin Homolog gene was also observed and a significant relationship was found between them. Castration resistance was observed in cases with high tumour volume, and a statistically significant difference was found. A statistically significant relationship was found between tumour volume and Ki-67 expression. In addition, a significant relationship was observed between the castration resistance and Ki-67, c-erbB2 expressions. A statistically significant relationship was found between Ki-67 and c-erbB2., Conclusion: Regarding prognosis prediction and treatment, identifying the molecular changes in genes playing roles in prostate cancer with next-generation sequencing is very important., (Copyright © 2024 Copyright: © 2024 Indian Journal of Pathology and Microbiology.)

Background and Objective: The demonstration of HER2 in gastric adenocarcinoma (GA) tissues by immunohistochemistry assists in deciding whether targeted therapy would optimise the treatment of GA patients who are HER2 positive. However, this has not been extensively studied in our patients hence the need for this study., Methods: Recipient tissue microarray blocks were constructed from donor archival formalin fixed paraffin embedded gastric tumour tissue from 80 patients seen over a period of 17 years in a retrospective descriptive study. Slides cut from these blocks were stained with antihuman HER2 antibody by immunohistochemistry and scored using the trastuzumab in gastric adenocarcinomas (ToGA) trial criteria. Data on age, gender, site of lesion and histological subtype of the gastric adenocarcinomas were also retrieved and reviewed., Results: Eighty cases (52 males and 28 females; male to female ratio of 1.9:1), 55.65 ±13.50 years (modal age group 60-69 years), were studied. Most tumours (91.2%) involved the distal parts (pylorus, antrum and body) with a few (8.8%) involving the proximal part (cardia and fundus) of the stomach. HER2 was overexpressed in a total of 6 (7.5%) cases only. Two of seven (28.6%) proximal tumours showed HER2 positivity whereas only 4 of 73 (5.5%) of the distal tumours showed HER2 positivity., Conclusion: We had only a slightly lower HER2 overexpression rate than in studies from many other parts of the world. The observed overexpression was significantly higher in proximal than distally located tumours suggesting that distal tumours are less likely to respond to Trastuzumab than proximal tumours. The known association of distal gastric tumours with Helicobacter pylori infection probably provides for a possible difference in the molecular aetiopathogenesis of GAs by site of occurrence. The exact mechanisms for proximal gastric carcinogenesis remain to be more clearly elucidated. More studies, including clinical trials with larger sample sizes, are recommended to elucidate this differential expression of HER2 in gastric adenocarcinoma., Competing Interests: The Authors declare that no competing interest exists, (Copyright © 2024 by West African Journal of Medicine.)

Secretory carcinoma (SC) is a low-grade salivary gland carcinoma characterized by recurrent ETV6 rearrangements. Most cases have ETV6-NTRK3 fusions, while the minority of cases have non-NTRK3 fusions, including ETV6-RET and ETV6-MET. Detection of the fusion partner has become important, as there are TRK or RET inhibitors that may benefit patients with advanced SC. Currently, there are different methods to detect gene rearrangement in SCs, such as next-generation sequencing, reverse transcription-polymerase chain reaction, or fluorescence in situ hybridization. Immunohistochemistry (IHC) has greater accessibility, quick turnaround time, and can serve as a screening tool for confirmatory molecular tests. Pan-TRK and RET antibodies have been used to detect gene fusions in different tumors. Here, pan-TRK and RET IHC assays were performed on 28 salivary gland SCs, including 27 cases with ETV6-NTRK3 and one with ETV6-RET fusion confirmed by fluorescence in situ hybridization. Pan-TRK staining was positive in 26/27 (96.3%) of NTRK3 fusion-positive SCs with a nuclear staining pattern in more than 50% of tumor cells, and negative in the RET-rearranged case. RET IHC showed positive staining in most cases (26/28), but only three cases (including the RET-rearranged case) had diffuse and strong staining. RET IHC can be considered an effective screening test when diffuse/strong reactivity is present in pan-TRK IHC-negative cases. This study showed that pan-TRK staining has high sensitivity and specificity for SC with NTRK3 fusion. Whereas pan-TRK IHC is a useful screening method, further studies are needed to assess the value of RET IHC as a second sequential step., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

The aim of this study is to reveal the potential roles of apoptosis markers (Bcl2 and p53), proliferation markers (Ki-67 and CyclD1), and the neuroendocrine marker Chromogranin A as markers for the radioresistance of rectal cancer. Statistically significant differences were found in the expression of p53, Ki-67, and Chromogranin A in groups of patients with and without a favorable prognosis after radiotherapy. The survival analysis revealed that the marker of neuroendocrine differentiation, Chromogranin A, also demonstrated a high prognostic significance, indicating a poor prognosis. Markers of proliferation and apoptosis had no prognostic value for patients who received preoperative radiotherapy. Higher Chromogranin A values were predictors of poor prognosis. The results obtained from studying the Chromogranin A expression suggest that the secretion of biologically active substances by neuroendocrine cells causes an increase in tumor aggressiveness.

The ability to combine multiple immunohistochemical (IHC) markers within a single tissue section facilitates the evaluation and detection of co-expressions, while saving tissue. A newly developed 5x multiplex (MPX) IHC staining of five different IHC markers (Basal cell cocktail (34βE12 + p63), p504s (SP116), ERG (EPR3864), Ki-67 (30-9), PSMA (EP192)) was applied on whole sections of n = 37 radical prostatectomies (RPE) including normal and cancerous tissue. Four different colors including brown, magenta, yellow and teal coded for different stainings, whereas magenta was used twice for nuclear Ki-67 and cytosolic / membranous PSMA. The staining of multiplex IHC was compared to single stains of ERG, PSMA and p504s. The proper staining of the basal cell cocktail and Ki-67 could be assessed by internal positive controls in the multiplex staining. The proportion of PSMA and p504s expression revealed a significant correlation between multiplex and single stains (p < 0.01) as well as a concordant staining pattern for ERG (n = 14 prostate cancers were identified ERG positive with both methods). Our proof of concept study demonstrates a robust staining pattern of all five different antibodies with this newly developed 5x MPX IHC. This approach facilitates the recognition of prostate cancer, in particular by adding PSMA in cases with low p504s expression., (Copyright © 2021 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Data on Mesothelin (MSLN) expression in human normal and cancerous tissues is controversial. We employed immunohistochemistry (IHC) on a tissue microarray (TMA) from 599 pancreatic cancers and 12 large tissue sections of pancreatitis. MSLN expression was highest in pancreatic adenocarcinomas (89%) and adenocarcinomas of the ampulla Vateri (79%), infrequent in pancreatitis and absent in 6 acinus cell carcinomas and normal pancreas. MSLN expression was unrelated to pathological tumor stage, grade, metastasis, and tumor-infiltrating CD8+ lymphocytes. In conclusion, pancreatic cancer may be ideally suited for putative anti- MSLN therapies, and MSLN may represent a suitable biomarker for pancreatic cancer diagnosis, especially on small biopsies.

Abstract: Pancreatic adenocarcinoma remains a chemotherapy-resistant and refractory malignancy with high mortality, unaffected by recent progress in anticancer treatment. Expression of estrogen receptors was detected almost 50 years ago, in both benign and malignant pancreatic cells. However, early preclinical studies in pancreatic cancer led to contradictory findings, and most clinical studies failed to demonstrate an effect with tamoxifen treatment. The identification of a second form of estrogen receptor seems to provide some explanation for these discrepancies. Predominantly expressed in malignant cells and structurally different from what was considered the only estrogen receptor, estrogen receptor β was recognized as a negative prognostic factor and a possible therapeutic target in pancreatic ductal adenocarcinoma. Therefore, findings of research before the identification of estrogen receptor β should be reconsidered, and further studies should be designed to reassess the expression and effect of this specific estrogen receptor type in pancreatic cancer., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Up to 22% of all gastric adenocarcinomas are of the microsatellite instability (MSI) subtype. This subtype may not benefit from conventional adjuvant chemotherapy but does respond to novel immunotherapies. A proportion of MSI gastric adenocarcinomas are associated with inherited disease, inferring an opportunity to screen for further cancers in the patient while also identifying at-risk relatives. Although the importance of MSI subtyping is clear, the methods of detection vary. The main techniques are MSI testing and mismatch repair (MMR) immunohistochemistry (IHC). This study compares a novel Idylla (Biocartis) MSI assay to MMR IHC across 50 biopsies of gastric adenocarcinoma. The methods were concordant across 48 cases. The two discrepant results demonstrated known difficulties in the interpretation of IHC. Idylla MSI testing presents several advantages over MMR IHC but both methods are well established in detecting this subtype of gastric adenocarcinoma. The methods are best regarded as complementary tests, performing most optimally when combined., Competing Interests: Competing interests: Idylla MSI assay equipment and cartridge supplies were provided by Idylla Biocartis., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The distribution of mucin phenotypes and their relationship with clinicopathological features in early differentiated gastric adenocarcinomas in a Chinese cohort are unknown. We aimed to investigate mucin phenotypes and analyse the relationship between mucin phenotypes and clinicopathological features, especially biological behaviours, in early differentiated gastric adenocarcinomas from endoscopic specimens in a Chinese cohort., Methods: Immunohistochemical staining of CD10, MUC2, MUC5AC, and MUC6 was performed in 257 tissue samples from patients with early differentiated gastric adenocarcinomas. The tumour location, gross type, tumour size, histological type, depth of invasion, lymphovascular invasion, mucosal background and other clinicopathological parameters were evaluated. The relationship between mucin phenotypes and clinicopathological features was analysed with the chi-square test., Results: The incidences of gastric, gastrointestinal, intestinal and null phenotypes were 21 %, 56 %, 20 and 3 %, respectively. The mucin phenotypes were related to histology classification (P < 0.05). The proportion of the gastric phenotype became greater during the transition from differentiated to undifferentiated (P < 0.05). Complete intestinal metaplasia was higher in the gastric and intestinal phenotypes than in the gastrointestinal phenotype (P < 0.05). Tumours with poorly differentiated adenocarcinoma were mainly of the gastric phenotype, which was significantly higher than that of purely differentiated tubular adenocarcinoma (P < 0.05), and the depth of invasion in the mixed type was deeper (P < 0.05). Neither recurrence nor metastasis was detected., Conclusions: The mucin phenotype of early-differentiated gastric adenocarcinoma has clinical implications, and the gastric phenotype has aggressive biological behaviour in early differentiated gastric cancers, especially in those with poorly differentiated adenocarcinoma or papillary adenocarcinoma components., (© 2021. The Author(s).)

Introduction: p16 immunostaining is considered as a surrogate marker for human papillomavirus (HPV)-related head and neck squamous cell carcinomas (HNSCC). Herein, the utility of p16 is evaluated in cytology specimens., Material and Methods: The electronic data of a large academic institution was searched for cytology cases accompanied by p16 (2014-2018). Cases were categorized based on body sites. P16 staining was quantified (negative [0%], focal/patchy, or diffusely positive [>70%]). HPV testing was correlated where available., Results: A total of 372 cases were included (male:female, 239:133). The largest differences in application of p16 between men and women were in head/neck cases (209 versus 59) and the abdominal cases (1 versus 33), respectively. p16 diffuse staining is seen in most squamous cell carcinomas, small cell carcinomas, and gynecologic serous carcinomas. p16 expression was patchy or negative in most adenocarcinoma, neuroendocrine carcinoma, spindle cell neoplasms, and benign conditions. HPV testing was done on 217 cases including 138 cases with strong p16 (127 HPV+/11 HPV-), 20 cases with focal/patchy P16 staining (6 HPV+/14 HPV-) and 59 cases with negative p16 staining (3 HPV+/56 HPV-)., Conclusions: Diffuse p16 staining aids in the diagnosis of HPV-related carcinomas, particularly HPV-related HNSCC, across the body and according to sex. In contrast, focal/patchy p16 staining does not correlate with HPV status across various body sites. In conclusion, intensity of p16 matters and should be correlated with cytomorphology, clinical history, and ancillary studies (eg, p40 immunostaining) for an accurate diagnosis and preventing diagnostic pitfalls., (Copyright © 2020 American Society of Cytopathology. Published by Elsevier Inc. All rights reserved.)

Sinonasal low-grade non-intestinal-type adenocarcinomas (LG non-ITACs) are uncommon tumors with unclear histogenesis, although they are presumed to arise from seromucous glands or respiratory epithelium. We investigated the clinicopathological and immunohistochemical features of the tumors, with particular attention to the transition area from the normal epithelium to neoplastic cells and concurrent lesions; these features were compared with those of 10 patients with chronic sinusitis, who served as a control group. Seventeen patients with LG non-ITACs (17 tumors) were enrolled in this retrospective study (9 male patients and 8 female patients; mean age, 48 years [range, 16-74 years]). Tumor cells continuous with respiratory epithelium were detected in 10 tumors composed of a single layer of cells with papillary, tubular, or cystic growth pattern. The tumor cells were uniformly cuboidal to columnar and polar. In seven tumors without transition areas discerned, three tumors consisted of polygonal and flat cells with a solid, acinar, micropapillary and cribriform pattern. The others had the same morphology as those with transition areas. The tumor cells were positive for SOX10 (15/17), S100 protein (8/17), and CK7 (17/17). The normal epithelium connected to the respiratory epithelium was the terminal duct in the control group. Except for the lack of p63-positive cells, the immunophenotype and histomorphology of transition areas with LG non-ITACs were similar to those of the continuous areas between the terminal duct and the respiratory epithelium in the control group. LG non-ITACs are seromucinous tumors, some of which may originate from the terminal ducts of seromucinous glands., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Mucinous adenocarcinoma of the rectum accounts for 10% of all rectal cancers and has an impaired response to neoadjuvant chemoradiotherapy and worse overall survival. To date, insufficient genomic research has been performed on this histological subtype., Objective: This study aims to define the mismatch repair deficiency rate and the driver mutations underpinning mucinous adenocarcinoma of the rectum and to compare it with rectal adenocarcinoma not otherwise specified., Design: Immunohistochemistry and sequencing were performed on tumor samples from our tumor biobank., Settings: This study was conducted across 2 tertiary referral centers., Patients: Patients with mucinous adenocarcinoma and rectal adenocarcinoma not otherwise specified who underwent rectal resection between 2008 and 2018 were included., Main Outcome Measures: Mismatch repair status was performed by immunohistochemical staining. Mutations in the panel of oncogenes and tumor suppressor genes were determined by sequencing on the MiSeq V3 platform., Results: The study included 33 patients with mucinous adenocarcinoma of the rectum and 100 patients with rectal adenocarcinoma not otherwise specified. Those with mucinous adenocarcinoma had a mismatch repair deficiency rate of 12.1% compared to 2.0% in the adenocarcinoma not otherwise specified cohort (p = 0.04). Mucinous adenocarcinoma and adenocarcinoma not otherwise specified rectal tumors had similar mutation frequencies in most oncogenes and tumor suppressor genes. No difference was found in the KRAS mutation rate (50.0% vs 37.1%, p = 0.29) or BRAF mutation rate (6.7% vs 3.1%, p = 0.34) between the cohorts. No difference was found between the cohorts regarding recurrence-free (p = 0.29) or overall survival (p = 0.14)., Limitations: The major limitations of this study were the use of formalin-fixed, paraffin-embedded tissue over fresh-frozen tissue and the small number of patients included, in particular, in the mucinous rectal cohort., Conclusions: Most mucinous rectal tumors develop and progress along the chromosomal instability pathway. Further research in the form of transcriptomics, proteomics, and analysis of the effects of the mucin barrier may yield valuable insights into the mechanisms of resistance to chemoradiotherapy in this cohort. See Video Abstract at http://links.lww.com/DCR/B464., Una Percepcin Sobre Mutaciones Impulsoras Y Mecanismos Moleculares Subyacentes Al Adenocarcinoma Mucinoso Del Recto: ANTECEDENTES:El adenocarcinoma mucinoso del recto, representa el 10% de todos los cánceres rectales y tiene una respuesta deficiente a la quimioradioterapia neoadyuvante y una peor supervivencia en general. A la fecha, se han realizado muy pocas investigaciones genómicas sobre este subtipo histológico.OBJETIVO:Definir la tasa de deficiencia en la reparación de desajustes y mutaciones impulsoras, que sustentan el adenocarcinoma mucinoso del recto y compararlo con el adenocarcinoma rectal no especificado de otra manera.DISEÑO:Se realizaron inmunohistoquímica y secuenciación en muestras tumorales de nuestro biobanco de tumores.AJUSTE:El estudio se realizó en dos centros de referencia terciarios.PACIENTES:Se incluyeron pacientes con adenocarcinoma mucinoso y adenocarcinoma no especificado de otra manera, sometidos a resección rectal entre 2008 y 2018.PRINCIPALES MEDIDAS DE RESULTADO:El estado de reparación de desajustes se realizó mediante tinción inmunohistoquímica. Las mutaciones en el panel de oncogenes y genes supresores de tumores, se determinaron mediante secuenciación en la plataforma MiSeq V3.RESULTADOS:El estudio incluyó a 33 pacientes con adenocarcinoma mucinoso del recto y 100 pacientes con adenocarcinoma del recto no especificado de otra manera. Aquellos con adenocarcinoma mucinoso, tenían una tasa de deficiencia de reparación de desajustes del 12,1% en comparación con el 2,0% en la cohorte de adenocarcinoma no especificado de otra manera (p = 0,04). El adenocarcinoma mucinoso y el adenocarcinoma no especificado de otra manera, tuvieron frecuencias de mutación similares en la mayoría de los oncogenes y genes supresores de tumores. No se encontraron diferencias en la tasa de mutación de KRAS (50,0% frente a 37,1%, p = 0,29) o la tasa de mutación de BRAF (6,7% frente a 3,1%, p = 0,34) entre las cohortes. No se encontraron diferencias entre las cohortes con respecto a la supervivencia libre de recurrencia (p = 0,29) o la supervivencia global (p = 0,14).LIMITACIONES:Las mayores limitaciones de este estudio, fueron el uso de tejido embebido en parafina y fijado con formalina, sobre el tejido fresco congelado y el pequeño número de pacientes incluidos, particularmente en la cohorte mucinoso rectal.CONCLUSIONES:La mayoría de los tumores rectales mucinosos se desarrollan y progresan a lo largo de la vía de inestabilidad cromosómica. La investigación adicional en forma transcriptómica, proteómica y análisis de los efectos de la barrera de la mucina, puede proporcionar información valiosa sobre los mecanismos de resistencia a la quimioradioterapia, en esta cohorte. Consulte Video Resumen en http://links.lww.com/DCR/B464., (Copyright © The ASCRS 2021.)

Numerous studies have shown a correlation between perineural invasion (PNI) in prostate biopsies and outcome. The reporting of PNI varies widely in the literature. While the interobserver variability of prostate cancer grading has been studied extensively, less is known regarding the reproducibility of PNI. A total of 212 biopsy cores from a population-based screening trial were included in this study (106 with and 106 without PNI according to the original pathology reports). The glass slides were scanned and circulated among four pathologists with a special interest in urological pathology for assessment of PNI. Discordant cases were stained by immunohistochemistry for S-100 protein. PNI was diagnosed by all four observers in 34.0% of cases, while 41.5% were considered to be negative for PNI. In 24.5% of cases, there was a disagreement between the observers. The kappa for interobserver variability was 0.67-0.75 (mean 0.73). The observations from one participant were compared with data from the original reports, and a kappa for intraobserver variability of 0.87 was achieved. Based on immunohistochemical findings among discordant cases, 88.6% had PNI while 11.4% did not. The most common diagnostic pitfall was the presence of bundles of stroma or smooth muscle. It was noted in a few cases that collagenous micronodules could be mistaken for a nerve. The distance between cancer and nerve was another cause of disagreement. Although the results suggest that the reproducibility of PNI may be greater than that of prostate cancer grading, there is still a need for improvement and standardization.

We investigated the expression of LGR5, the most robust and reliable known cancer stem cell (CSC) marker of colorectal cancer, and PD-L1 in tumor budding (TB), as well as clinicopathological features. Tissue microarrays (TMAs) were generated from TB samples from 32 stage II/III colorectal adenocarcinoma patients, and LGR5 expression in TMAs was evaluated by RNAscope, an extremely sensitive RNA in situ hybridization technique. LGR5 expression was significantly lower in the PD-L1-positive group than in the PD-L1-negative group (P = 0.0256). In the PD-L1-positive group, the tumor-infiltrating lymphocytes (TILs) score tended to be higher while the TNM stage was lower compared with the PD-L1 negative group (P = 0.0822 and P = 0.0765, respectively). There was no significant difference in Overall Survival between the PD-L1-positive and PD-L1-negative groups (log-rank test, P = 0.8218). This study showed that PD-L1-positive patients are a unique population with low LGR5 expression, and that LGR5-positive cells may be a promising therapeutic target in PD-L1-negative patients., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Introduction: This retrospective morphological study compared the results of fine needle aspiration (FNA) cytology, haematoxylin-eosin (HE)-stained samples and immunohistochemical (IHC)-stained core needle biopsy (CNB) histology samples for primary non-small cell lung cancer (NSCLC) subtyping. We assessed the diagnostic utility of these methods to investigate the contribution of each method to NSCLC subtyping. We also identified the point at which NSCLC subtyping could be performed using histomorphology alone without IHC., Methodology: Concurrent FNA and CNB specimens obtained via a single computed tomography-guided procedure and diagnosed as NSCLC in the Pathology Department of our university within 3 years were reviewed. The results of FNA samples, HE-stained biopsies and IHC-stained biopsies were compared according to subtype., Results: A total of 141 subjects were enrolled in the study. For subtyping, FNA provided an accurate diagnosis in 70 (55.1%) of 127 eligible subjects after the exclusion of 14 cases determined as not otherwise specified. CNB histology without IHC achieved a diagnosis in 53 (41.7%) of 127 subjects, which was a significant difference (P < .05). The compatibility rate between HE-stained biopsy samples and IHC-stained biopsy samples was 41.7% (53/127)., Conclusion: The diagnosis rates achieved using FNA, HE-stained CNB samples and IHC-stained CNB samples were 54.6% (77/141), 37.6% (53/141) and 90.1% (127/141), respectively. The subtype was identified in 55.1% of the subjects evaluated using FNA and 41.7% of subjects assessed using HE-stained biopsy samples without IHC. FNA provided a better result for squamous cell carcinoma than adenocarcinoma (55.1% vs 47.6%), but the diagnosing of adenocarcinoma and squamous cell carcinoma using HE-stained biopsy samples was similar (42% vs 41.7%)., (© 2020 John Wiley & Sons Ltd.)

Introduction: Second primary nonlymphoid malignancies (SPNLM) have long been recognized as a complication of chronic lymphocytic leukemia (CLL)., Materials and Methods: A search was made of our cytopathology database for cases of CLL that also contained a SPNLM., Results: Seventeen cases from 13 known CLL patients [M:F = 2.3:1; age range: 47-77 years, x = 67 years] met criteria for this study. SPNLMs consisted of different forms of metastatic carcinoma (10 patients) and malignant melanoma (3). Of 16 FNA biopsies and 1 pleural fluid, 82% had ancillary testing; 35% had the specimen subdivided for both flow cytometry (FCM) and immunohistochemistry (IHC). Lymph node was the most common site for FNA biopsy (12), followed by face (2), and soft tissue (2). Squamous cell carcinoma was the most common SPNLM (6), followed by melanoma (3), and there were single cases of adenocarcinoma, large cell neuroendocrine carcinoma, Merkel cell carcinoma, and papillary thyroid carcinoma. A correct specific cytologic diagnosis was made in 15 (88%) cases., Conclusions: Cytopathology is highly proficient in recognizing SPNLM in CLL patients. Utilization of cytologic material for FCM and IHC is feasible, and extremely helpful in achieving diagnostic accuracy., (Copyright © 2021 American Society of Cytopathology. Published by Elsevier Inc. All rights reserved.)

Spiradenocarcinoma (SC) is a very rare malignant skin adnexal tumor with sweat gland differentiation that develops from a pre-existing spiradenoma, cylindroma, or hybrid tumor called spiradenocylindroma, or arises de novo. We present two exceptionally rare SC cases showing sarcomatous differentiation; we also discuss the clinicopathologic features of SC, as well as its differential diagnoses and available therapeutic modalities. Given the aggressive behavior of SC, rapid diagnosis and complete removal of the tumor with tumor-free margins is mandatory. Owing to the marked morphological heterogeneity of individual SC cases, dermatopathologists must be familiar with the different possible histopathologic manifestations of this neoplasm., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: Any type of cutaneous metastasis indicates dismal outcome of the disease. Skin is an unusual location for metastatic deposits from any tumour and has an incidence of about 0.8%-5%. Fine needle aspiration cytology (FNAC) helps in the rapid diagnosis of metastasis with minimum pain., Aim: To study the cytomorphological spectrum of cutaneous metastasis on FNAC., Material and Methods: A total of 225 patients with diagnosis of cutaneous metastasis on cytology were analysed. May-Grünwald Giemsa and haematoxylin-eosin-stained smears were studied and examined for the cytomorphological spectrum of cutaneous metastasis. Cell block was prepared in a few cases. In a subset of cases, immunohistochemistry was done to pinpoint the primary., Results: Amongst the 225 patients studied, the mean age was 53.9 years. There was female preponderance with 125 females and 100 males. The commonest site was abdominal wall (n = 89) followed by chest wall (n = 60). The most common type of metastasising tumour was adenocarcinoma., Conclusion: Clinicians and pathologists must be aware of the clinico-morphological spectrum of cutaneous metastasis for instant diagnosis followed by prompt management., (© 2020 John Wiley & Sons Ltd.)

Background/aim: Small bowel adenocarcinoma (SBA) is a relatively rare malignant epithelial neoplasm. Thus, little is known about prognostic biomarkers of SBA. Annexin A10 (ANXA10) is a member of the annexin family. The significance of ANXA10 expression in SBA is unclear. This is the first study to examine the expression of ANXA10 in SBA., Materials and Methods: We immunohistochemically evaluated ANXA10 expression of SBA and studied the relationship between ANXA10 expression and clinicopathological factors., Results: ANXA10 expression was detected in 17 (56.7%) of 30 SBA cases and was significantly associated with poor overall survival. Univariate predictors for poor prognosis were tumour size (p=0.017) and ANXA10 expression (p=0.026). In multivariate analysis, ANXA10 expression (p=0.038) and tumour size (p=0.024) were found to be independent predictors of poor prognosis., Conclusion: ANXA10 could be a new prognostic biomarker for SBA., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: TROP-2, a novel marker of trophoblastic cells, is being widely analyzed for its possible role in carcinogenesis and clinical behavior of various carcinomas. In this study, we aimed to evaluate the relationship between clinicopathologic parameters and TROP2 expression in prostatic adenocarcinomas., Methods: 101 prostatic adenocarcinomas treated by radical prostatectomy in our hospital between 2013 and 2018 were reviewed retrospectively for histopathological features, and one representative block of each case was stained with TROP2 antibody. Histopathologic prognostic features were assessed for their relationship with TROP2 expression., Results: The mean age was found as 64.11 year. TROP2 was stained in over 10% of the tumoral cells in 64 (63.4.%) cases. Gleason grade group, perineural invasion, lymphovascular invasion, ganglionic and seminal vesicle involvement, lateral and basal surgical margin positivity showed a significant relationship with TROP2 staining., Conclusion: TROP2 is overexpressed in various human cancers and TROP2 overexpression appears to correlate with poor prognosis leading to the suggestion that TROP2 could be a therapeutic target for various carcinomas. Our results suggest that TROP2 expression is higher in advanced tumors and these results need to be supported by larger studies., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The aim of the study was to investigate 3D texture analysis (3D-TA) in noncontrast enhanced computed tomography (CT) (NCECT) to differentiate squamous cell carcinoma (SCC) from adenocarcinoma (AC), and the correlation with immunohistochemical markers., Methods: A total of 70 patients confirmed with SCC (n = 29) and AC (n = 41) were enrolled in this retrospective study. 3D-TA was utilized to calculate TA parameters of all the tumor lesions based on NCECT images, and all the patients were divided into the training and the test groups. The TA parameters were selected by dimensionality reduction, and the model was established to differentiate SCC from AC according to the training group. The ROC curve was used to evaluate the diagnostic efficiency of the model in both the training and the test groups. Spearman correlation were used to assess the correlation between the selected feature parameters and immunohistochemical markers (P63, P40, and TTF-1)., Results: Five TA parameters, including volume count, relative deviation, Haralick correlation, gray-level nonuniformity and run length nonuniformity, were obtained to differentiate SCC from AC by multistep dimensionality reduction. The new model combined with all five TA parameters yielded a high diagnostic performance to differentiate SCC from AC (AUC 0.803) in test group, with a specificity of 89% and a sensitivity of 77%. There was weak correlation between the five texture feature parameters and P63 as well as P40 in all patients (P < 0.05), respectively., Conclusions: The model including five TA parameters on NECT has a good diagnostic performance in differentiating SCC from AC., Key Points: • Significant findings of the study The model created by five selected textural feature parameters can differentiate solid SCC from AC without contrast media. The selected five texture feature parameters are correlated to the immunohistochemical markers P63 and P40. • What this study adds The textural feature parameters' model can identify SCC from AC without contrast media., (© 2020 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Introduction: Immune checkpoint pathway markers induce immune tolerance to non-small cell lung cancer (NSCLC). Therapeutic antibodies targeting the programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway have demonstrated efficacy in tumors expressing relatively high PD-L1 levels. Minimally invasive endobronchial ultrasound-guided fine needle aspiration allows patients with inoperable tumors or comorbidities to attain a confirmatory diagnosis. The aims of the present study were to determine whether PD-L1 testing is equivalent to cytology and biopsy or resection specimens at different tumor proportion score cutoffs and for different NSCLC subtypes., Materials and Methods: Data were retrospectively collected for patients with paired NSCLC cytology and surgical resection specimens from May 4, 2007 to May 4, 2017. The Food and Drug Administration-approved Dako PD-L1 immunohistochemistry 22C3 pharmDx kit was used to measure PD-L1 on paired cytology cell block and biopsy or resection specimens, and the PD-L1 tumor proportion scores were recorded. Statistical analysis of categorical and continuous variables was performed using SAS, version 9.4., Results: A total of 53 paired cytology and resection samples (27 adenocarcinoma, 25 squamous cell carcinoma, and 1 unclassified) were analyzed. Supposing the resection specimen to reflect the true PD-L1 expression, the sensitivity, specificity, positive predictive value, negative predictive value, and overall agreement for the cytology method was 73.3%, 65.2%, 73.3%, 65.2%, and 69.8%, respectively. For high PD-L1 expression (≥50%), the cytology method demonstrated an overall agreement of 79.2%. The overall agreement between methods was 81.5% and 76% for cases of adenocarcinoma and squamous cell carcinoma, respectively., Conclusions: NSCLC cytology samples from endobronchial ultrasound-guided fine needle aspiration are suitable for PD-L1 testing, especially using a high PD-L1 expression cutoff of ≥50% and for adenocarcinoma., (Copyright © 2020 American Society of Cytopathology. Published by Elsevier Inc. All rights reserved.)

Background: Crawling-type adenocarcinoma (CRA) is an important gastric cancer (GC) subtype that exhibits a specific histological pattern and has characteristic clinicopathological findings. Despite its characteristic histology, little is known about the molecular characteristics of CRA., Methods: We examined 177 GC cases, including 51 cases of CRA and 126 cases having conventional differentiated adenocarcinomas (CDAs). Results for immunohistochemistry (mucin phenotype; Muc5AC, Muc6, Muc2 and CD10, CDX-2, MLH-1, p53 and β-catenin), mutation analysis (TP53, KRAS and BRAF), microsatellite instability (BAT25, BAT26, D2S123, D5S346 and D17S250), DNA methylation status by a two-panel method (RUNX3, MINT31, LOX, NEUROG1, ELMO1 and THBD), MLH-1 promoter methylation, and allelic imbalance (AI; 1p, 3p, 4p, 5q, 8p, 9p, 13q, TP53, 18q and 22q) were examined., Results: CRAs were more likely to occur in the middle third of the stomach, in younger patients and to be macroscopically depressed. Nuclear accumulation of β-catenin and loss of MLH-1 expression were less frequent among CRA cases compared to CDA cases. At a molecular level, CRA is often characterized by the deletion mutation c.529&#95;546 (18-base pair deletion at codon 177-182 in exon 5) in the TP53 gene (10 cases). Although the low methylation epigenotype was significantly more frequent for CRAs compared to CDAs, multiple AIs were more often seen in CRAs relative to CDAs., Conclusions: The results demonstrated that TP53 mutations, particularly c.529&#95;546del, and multiple AIs are closely associated with CRA carcinogenesis. Our results suggest that CRA is an independent entity of GC in terms of clinicopathologic and molecular findings.

Diagnosis of gastric adenocarcinoma using small biopsy samples is occasionally difficult. Various markers have been employed for improving the diagnostic accuracy, but there remains room for improvement. A total of 129 endoscopically biopsied samples were studied, consisting of 104 intramucosal tubular adenocarcinomas, 24 non-cancerous lesions and one cancer sample originally suspected of non-cancer but revised as cancer after immunostaining. We evaluated the association between histopathology and immunohistochemical expression of MUC1, HER2, p53, CEA, E-cadherin, β-catenin and claudin-18. Regarding β-catenin and claudin-18, not only membranous expression (β-catenin(M) and claudin-18(M)) but also nuclear expression (β-catenin(N) and claudin-18(N)) were analyzed. When subtyped with mucin core protein expression, the gastric-type cancers dominantly expressed claudin-18(M), while claudin-18(N) was significantly encountered in intestinal- and mixed-types. Expression of MUC1 (P = 0.0010), HER2 (P = 0.0173), p53 (P = 0.0002), CEA (P = 0.0019) and claudin-18(N) (P < 0.0001) revealed significant correlation with gastric cancers. Negative correlation of claudin-18(M) (P = 0.0125) was also noted. MUC1 and p53 were negative in non-cancer lesions. The non-cancer group exceptionally expressed HER2 and β-catenin(N). Membranous expression of E-cadherin was consistent in both groups. Logistic regression analysis showed that MUC1 (P = 0.0086), p53 (P = 0.0031), claudin-18(M) (P = 0.0158) and claudin-18(N) (P = 0.0190) were independently associated with gastric cancers. Nuclear expression of claudin-18 should be the novel diagnostic marker for gastric cancer., (© 2020 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Introduction: Microsatellite instability (MSI) testing is recommended for all colonic and endometrial carcinomas to screen for Lynch syndrome. The role of MSI testing in pancreatic adenocarcinoma has not been well-established. Screening can be done via immunohistochemical (IHC) staining for mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, PMS2). We report our experience and the clinical utility of MMR IHC on pancreatic adenocarcinomas in fine-needle aspiration (FNA) specimens., Materials and Methods: We performed a retrospective review to identify all patients diagnosed with pancreatic adenocarcinoma by FNA at our institution between December 2017 and September 2019. For cases with sufficient tumor cells for testing, the MMR results and morphology were summarized, as well as corresponding clinical information, including age, clinical stage, treatment, and concurrent other cancers., Results: From December 2017 to September 2019, there were a total of 184 pancreatic FNAs with a diagnosis of adenocarcinoma. Of these 184 FNAs, 65 (35%) contained sufficient material in the cell block to perform IHC for MMR. The cell block material was collected in either RPMI or CytoLyt. Poor technical quality precluded interpretation of PMS2 in 4 cases and MSH6 in 2 cases. All other cases showed intact expression of all four proteins., Conclusions: IHC for MMR proteins can be done on specimens collected in RPMI or CytoLyt, but RPMI appears to be more reliable. None of the pancreatic adenocarcinomas in this study showed loss of MMR protein expression. Routine testing of MMR loss may not be indicated in pancreatic adenocarcinomas in the general patient population., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Differentiating between malignant and normal cells within tissue samples is vital for molecular profiling of cancer using advances in genomics and transcriptomics. Cell-surface markers of tumour-normal discrimination have additional value in terms of translatability to diagnostic and therapeutic strategies. In gastric cancer (GC), previous studies have identified individual genes or proteins that are upregulated in cancer. However, a systematic analysis of cell-surface markers and development of a composite panel involving multiple candidates to differentiate tumour from normal has not been previously reported., Methods: Whole transcriptome sequencing (WTS) of GC and matched normal samples from the Singapore Gastric Cancer Consortium (SGCC) was used as a discovery cohort to identify upregulated putative cell-surface proteins. Matched WTS data from the The Cancer Genome Atlas (TCGA) was used as a validation cohort. Promising candidates from this analysis were validated orthogonally using multispectral immunohistochemistry (mIHC) with automated quantitative analysis using the Vectra platform. mIHC was performed on a tissue microarray containing matched normal, marginal and tumour tissues. The receiver-operating characteristic (ROC) curves were analysed to identify markers with the highest diagnostic validity independently and in combination., Results: Analysis of putative membrane protein transcripts from the SGCC discovery cohort WTS data (n=15 matched tumour and normal pairs) identified several differentially and highly expressed candidates in tumour compared with normal tissues. After validation with TCGA data (n=29 matched tumour and normal pairs), the following proteins were selected for mIHC analysis: CEACAM5, CEACAM6, CLDN4, CLDN7, and EpCAM. These were compared with established glycoprotein markers in GC, namely CA19-9 and CA72-4. Individual ROC curves yielded the best performance for CEACAM5 (area under the ROC curve (AUC)=0.80), CEACAM6 (AUC=0.82), EpCAM (AUC=0.83), and CA72-4 (AUC=0.76). Combined multiplexed imaging of these four markers revealed improved specificity and sensitivity for detection of tumour from normal tissue (AUC of 4-plex=0.91)., Conclusion: CEAMCAM5, CEACAM6, EpCAM, and CA72-4 form a versatile set of markers for robust discrimination of GC from adjacent normal tissue. As cell-surface markers, they are compatible with both IHC and live imaging approaches. These candidates may be exploited to improve automated identification of tumour tissue in GC., Competing Interests: Competing interests: AJ: honoraria from AstraZeneca, Janssen and MSD, travel funding from Perkin Elmer, and research funding from Janssen. RS: Advisory board: BMS, Merck, Eisai, Bayer, Taiho; honoraria for talks: MSD, Eli Lilly, BMS, Roche, Taiho; Travel funding: Roche, Astra Zeneca, Taiho, Eisai; Research funding: Paxman Coolers, MSD., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Indoleamine 2,3-dioxygenase 2 (IDO2) is an analog of the tryptophan degrading and immunomodulating enzyme indoleamine 2,3-dioxygenase 1 (IDO1). Although the role of IDO1 is largely understood, the function of IDO2 is not yet well-elucidated. IDO2 overexpression was documented in some human tumors, but the linkage between IDO2 expression and cancer progression is still unclear, in particular in non-small cell lung cancer (NSCLC). Immunohistochemical expression and cellular localization of IDO2 was evaluated on 191 formalin-fixed and paraffin-embedded resected NSCLC. Correlations between IDO2 expression, clinical-pathological data, tumor-infiltrating lymphocytes (TILs), immunosuppressive tumor molecules (IDO1 and programmed cell death ligand-1 - PD-L1 -) and patients' prognosis were evaluated. IDO2 high expression is strictly related to high PD-L1 level among squamous cell carcinomas group ( p = 0.012), to either intratumoral or mixed localization of TILs ( p < 0.001) and to adenocarcinoma histotype ( p < 0.001). Furthermore, a significant correlation between IDO2 high expression and poor non-small cell lung cancer prognosis was detected ( p = 0.011). The current study reaches interesting knowledge about IDO2 in non-small cell lung cancer. The close relationship between IDO2 expression, PD-L1 increased levels, TILs localization and NSCLC poor prognosis, assumed IDO2 as a potential prognostic biomarker to be exploited for optimizing innovative combined therapies with immune checkpoint inhibitors., (Copyright © 2020 Mandarano, Bellezza, Belladonna, Vannucci, Gili, Ferri, Lupi, Ludovini, Falabella, Metro, Mondanelli, Chiari, Cagini, Stracci, Roila, Puma, Volpi and Sidoni.)

A classification system for invasive endocervical adenocarcinoma (ECA) focusing on high-risk human papillomavirus (HPV) detection has been recently developed. However, precursor lesions of each ECA subtype and immunohistochemical markers that effectively subcategorize ECAs with gastric and intestinal differentiation have not been fully described. Here, we aimed to subcategorize endocervical adenocarcinoma in situ (AIS) by immunophenotype and to characterize the histopathology of each AIS subtype. We immunohistochemically analyzed 36 AIS and 25 lobular endocervical glandular hyperplasia (LEGH) samples using three cell lineage-specific markers (CLDN18, gastric epithelial cells; CDH17, intestinal epithelial cells; and PAX8, Müllerian epithelial cells). The AISs were immunophenotypically classified as gastric-type (G-AIS; n = 2), intestinal-type (I-AIS; n = 10), gastrointestinal-type (GI-AIS; n = 3), Müllerian-type (M-AIS; n = 18), and AIS, not otherwise specified (AIS-NOS; n = 3). All 25 LEGHs were categorized as gastric-type. G-AIS had pale eosinophilic or clear cytoplasm with a small amount of apical mucin and fewer mitotic bodies. I-AIS comprised various numbers of goblet cell-type tumor cells. GI-AIS showed intermediate or mixed features of G-AIS and I-AIS. M-AIS, as with the usual-type ECA, was typically characterized by mucin depletion; however, several lesions had abundant cytoplasmic mucin. High-risk HPV was detected in most AISs but was negative in 100% (2/2) of G-AIS, 10% (1/10) of I-AIS, and 6% (1/18) of M-AIS lesions. In summary, the AIS subtypes defined by immunophenotype had distinct histopathological and etiological characteristics. Thus, immunophenotyping with CLDN18, CDH17, and PAX8 might improve the diagnostic accuracy of histopathological classifications of ECAs.

Esophageal cancer (EC) is one of the most lethal malignancies of the digestive tract and remains to be improved poor prognosis. Two histological subtypes, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), are major characteristics of EC. Deep understanding about both subtypes is essential to overcome EC. Here, we focus on chemokines and their receptors as biomarkers and their current applications for the prognosis in EC. We reviewed relevant articles identified using PubMed database for the chemokines and their receptors in EC analyzed by immunohistochemistry. The primary objective is to summarize evidences for them as prognostic biomarkers in EC. A total of twenty-one articles were reviewed after exclusion. Most studies have been done in ESCC, and less in EAC. CXCL12 and its receptor CXCR4 have been shown in both subtypes as biomarkers. CXCR7, CXCL8 and its receptor CXCR2, and CCL21 and its receptor CCR7 have been examined in ESCC. Although it was a small number of reports, CXCL10, CCL4, and CCL5 have been indicated to have anti-tumor effects in ESCC. Chemokines and their receptors have the potential to be the biomarkers in EC. Comparative studies between ESCC and EAC will reveal the similarity and difference in these two subtypes of EC. These studies may indicate whether these molecules play important roles in both subtypes or are unique to one or another.

Focal adhesion kinase (FAK), a member of the non-receptor cytoplasmic tyrosine kinase family, is associated with the development and progression of cancer. Matrix metalloproteinase-9 (MMP-9) is directly involved in the degradation of the extracellular matrix, and basement membrane components promote cancer cell migration and invasion. There is a functional interaction among FAK, MMP-9 and vascular endothelial growth factor (VEGF), which leads to enhanced cancer angiogenesis, cancer cell invasion and progression of malignancy. FAK, MMP-9, VEGF and CD34-positive microvessel density (MVD) were examined in 100 patients with prostate adenocarcinoma using immunohistochemistry. The relationship among these proteins and their impact on angiogenesis and clinicopathological parameters were also evaluated. The FAK expression was found to be positively correlated with the Gleason score, WHO grade group, tumour stage, extracapsular extension and perineural invasion. The MMP-9 expression was positively correlated with the WHO grade group, tumour stage, extracapsular extension, positive surgical margin and lymphovascular and perineural invasion. The FAK expression was also positively correlated with MMP-9 expression and MVD. However, no correlation between FAK and VEGF expression was identified. The MMP-9 expression was positively correlated with FAK expression and MVD. Strong MMP-9 expression was associated with shorter disease-free survival. These results suggest that strong MMP-9 and FAK expressions play an essential role in the progression of prostate adenocarcinoma. Further investigations should be conducted to determine the importance of these proteins as therapeutic targets for patients with prostate adenocarcinomas., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Neoadjuvant treatment (NAT) followed by total mesorectal excision is currently considered the standard of treatment for rectal adenocarcinoma. The degree of pathologic treatment response (pTR) correlates significantly with the recurrence free survival and overall survival (OS). However, it remains unclear which clinical and pathologic factors are associated with a more robust response to NAT, including showing pathologic complete response (pCR). Chemokine receptor 4 (CXCR4) overexpression has been associated with unfavorable OS in some studies. In this study, we sought to evaluate the clinicopathologic determinants of pTR in neoadjuvant treated rectal adenocarcinoma (NAT-RA). We retrospectively identified 91 patients who underwent pre-treatment diagnostic biopsy, NAT, and surgical resection at our institution. The archival slides were reviewed for pathologic features in the pre-treatment biopsies and for assessment of pTR in the resection specimens according to the current College of American Pathologist (CAP)'s guidelines. pCR was obtained in 16.5% of the cases, whereas 20.9% had near pCR, 30.8% had partial response, and 31.9% had a poor/no response. CXCR4 immunohistochemical analysis was also performed on the pre-treatment biopsies. Lower pre-treatment cT-stage (p = 0.019) and pre-treatment AJCC cTNM stage groups (p = 0.004), longer time interval between completion of NAT and resection (p = 0.022), and presence of tumor-infiltrating lymphocytes in the pre-treatment biopsies (p = 0.019) were significantly associated with a better pTR. CXCR4 nuclear expression was associated with a lower percentage of residual tumor (p = 0.036). Pre-treatment CEA levels, tumor differentiation, CAP treatment response groups and lower percentage of residual tumor were associated with a better OS., Competing Interests: Declaration of competing interest None of the authors have any relationships with, or financial interest in, any commercial companies pertaining to this article., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Platinum-based chemotherapy is part of the standard treatment for patients with colorectal cancer. ERCC1 is a potential predictive biomarker for platinum-based chemotherapy. The aim of this study was to examine interobserver agreement on ERCC1 protein expression in primary colorectal cancer as well as corresponding liver metastasis. Furthermore, comparison of ERCC1-expression in primary tumor and the corresponding liver metastasis was performed., Methods: Forty patients with primary colorectal cancers and corresponding liver metastases were included. One slide was stained with the anti-ERCC1 antibody, 4F9 clone (DAKO) and evaluated by two gastrointestinal pathology consultants and a pathology registrar separately. Interobserver agreement was evaluated for primary tumors and liver metastases using kappa (κ) statistics. Discordant scorings were reviewed, and consensus was obtained. The expression in primary tumor was compared with the corresponding liver metastases., Results: For the primary tumors agreement was found in 85% of the tumors corresponding to an unweighted kappa value of 0,79 (95% CI 0,64-0,94). For the liver metastases agreement was found in 76% corresponding to an unweighted kappa value of 0,64 (95% CI 0,49-0,79). When comparing primary tumors to the corresponding metastases, no concordance in ERCC1-expression was observed., Conclusion: Interobserver agreement of ERCC1 expression was good for both primary tumors and liver metastases, which is crucial for a potential predictive biomarker. As no concordance between primary tumor and liver metastases was found it seems to be of high importance to use tissue from actual tumor burden for evaluation of ERCC1 expression. Further studies and correlation to clinical outcome are warranted., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Context.—: The incidence of neuroendocrine tumors of the prostate increases after hormonal therapy. Neuroendocrine tumors possess a broad spectrum of morphologic features and pose challenges in the pathologic diagnosis and clinical management of patients., Objective.—: To present a brief updated summary of neuroendocrine tumors of the prostate with an overview of their histopathologic and immunohistochemical profiles and differential diagnoses., Data Sources.—: Literature review, personal experience in the daily practice of pathologic diagnosis, and laboratory research., Conclusions.—: Our understanding of neuroendocrine tumors of the prostate classification and diagnosis continues to evolve. These advances benefit the risk stratification and management of prostate cancer.

Objective: To investigate the cytological findings of lobular endocervical glandular hyperplasia (LEGH) associated with adenocarcinoma and to clarify its characteristics and the coexisting adenocarcinoma using histochemistry and immunohistochemistry., Methods: Eighteen surgical cases of LEGH of the uterine cervix were retrospectively reviewed and classified into 3 groups: pure (pure type), atypical (atypical type), and LEGH with adenocarcinoma (mixed type). The mixed type is defined as LEGH or atypical LEGH with in situ or invasive adenocarcinoma. Cytological findings of conventional endocervical smear specimens (Papanicolaou stain) were analyzed. Histochemistry (periodic acid-Schiff reaction) and immunohistochemistry (M-GGMC-1, Muc-6 glycoprotein, and Ki-67) were performed using tissue specimens., Results: Cytologically, the pure type (7 cases) is characterized by glandular cell clusters that tended to form monolayered sheets with uniformly small nuclei and contain golden-yellowish mucin, whereas atypical (5 cases) and mixed (6 cases) types are characterized by glandular cell clusters similar to those of the pure type, but with complex glandular structures and mucin localization on the surface of glandular cell clusters. Ki-67 labeling index was significantly higher in atypical and mixed types than that in the pure type. Gastric-type mucinous carcinoma (MC-G) was observed in 2 out of 6 cases with mixed type., Conclusions: LEGH is found to be associated with adenocarcinoma types other than MC-G. Complex glandular structures or mucin localization on the surface of glandular cell clusters may be useful cytological findings to detect atypical and mixed types of LEGH., (© 2020 S. Karger AG, Basel.)

Cancers occurring at the gastroesophageal junction (GEJ) are classified as predominantly esophageal or gastric, which is often difficult to decipher. We hypothesized that the transcriptomic profile might reveal molecular subgroups which could help to define the tumor origin and behavior beyond anatomical location. The gene expression profiles of 107 treatment-naïve, intestinal type, gastroesophageal adenocarcinomas were assessed by the Illumina-HTv4.0 beadchip. Differential gene expression (limma), unsupervised subgroup assignment (mclust) and pathway analysis (gage) were undertaken in R statistical computing and results were related to demographic and clinical parameters. Unsupervised assignment of the gene expression profiles revealed three distinct molecular subgroups, which were not associated with anatomical location, tumor stage or grade (p > 0.05). Group 1 was enriched for pathways involved in cell turnover, Group 2 was enriched for metabolic processes and Group 3 for immune-response pathways. Patients in group 1 showed the worst overall survival (p = 0.019). Key genes for the three subtypes were confirmed by immunohistochemistry. The newly defined intrinsic subtypes were analyzed in four independent datasets of gastric and esophageal adenocarcinomas with transcriptomic data available (RNAseq data: OCCAMS cohort, n = 158; gene expression arrays: Belfast, n = 63; Singapore, n = 191; Asian Cancer Research Group, n = 300). The subgroups were represented in the independent cohorts and pooled analysis confirmed the prognostic effect of the new subtypes. In conclusion, adenocarcinomas at the GEJ comprise three distinct molecular phenotypes which do not reflect anatomical location but rather inform our understanding of the key pathways expressed., (© 2019 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Aims: Gastric-type endocervical adenocarcinoma (EA) is characterised by aggressive behaviour and pathogenesis independent of human papillomavirus infection. Because of its morphology and frequent mutation-pattern expression of p53, gastric-type EA may be confused with several types of endometrial carcinoma, particularly in biopsy and curettage specimens. HIK1083 and MUC6 are immunohistochemical markers used to support a diagnosis of gastric-type EA; however, the rates of expression of these markers in endometrial tumours are largely unknown. We therefore aimed to assess the expression of HIK1083 and MUC6 in a cohort of different types of endometrial carcinoma., Methods and Results: Ninety-one endometrial carcinomas (56 endometrioid, 16 clear cell, and 19 serous) from 91 patients treated with hysterectomy were included. A representative tumour block from each case was used for immunohistochemical staining with HIK1083 and MUC6. The percentage of stained cells (0-100%) and average staining intensity (weak, moderate, and strong) were recorded for both markers. None of 91 cases expressed HIK1083. In contrast, 66% (60/91) of cases showed at least focal expression of MUC6; importantly, 54 of 60 (90%) positive cases showed moderate or strong staining. Five of 60 (8%) cases showed MUC6 staining in ≥50% of tumour cells. Endometrioid tumours (49/56, 88%) were more likely to express MUC6 than cases of clear cell (1/16, 6%) or serous (10/19, 53%) carcinoma., Discussion: Endometrial carcinoma often expresses MUC6. In contrast, HIK1083 is consistently negative, and thus, when positive, is a more reliable marker for distinguishing gastric-type EA from some of its endometrial mimics., (© 2019 John Wiley & Sons Ltd.)

Objective: Immunocytochemistry (ICC) of serous effusion is an important tool for the diagnosis of benign and malignant cells. Our aim was to develop a modified liquid-based cytological technique for ICC (i.e., a modified LBC). Methods: Serous effusions of 110 cases were collected for cytological examination: 50 were negative for malignancy albeit benign mesothelium was found, and 60 were confirmed metastatic adenocarcinoma according to the modified LBC preparation. The latter were stained for EMA, Ber-EP4, Calretinin, and p63 then interpreted by both a cytotechnologist and a pathologist. A comparative analysis of the diagnostic results was conducted. Results: The results of the metastatic adenocarcinoma were 100% (60/60) positive for EMA and 91.7% (55/60) positive for Ber-Ep4 but negative for calretinin and p63. Cases negative for malignancy were 100% (50/50) positive for calretinin but negative for carcinoma markers. The difference between ‘positive for metastatic adenocarcinoma’ and ‘negative for malignancy’ in ICC was statistically significant (p < 0.001). Conclusion: The current study demonstrated that a panel marker, comprising EMA, Ber-EP4, and calretinin can be used for differentiating between cases of metastatic adenocarcinoma and benign mesothelium. The serous effusion specimen collected by the modified LBC technique is an effective preparation method for ICC.

Background: Challenges still exist in differentiating pancreatic adenocarcinoma from benign disease. The use of adjuvant testing of tissue biopsies has demonstrated potential diagnostic value. We designed a proof of concept study to first validate four individual immunohistochemistry biomarkers and then combine them into a panel to boost overall diagnostic sensitivity., Methods: Malignant and benign pancreas from 27 pancreaticoduodenectomy specimens underwent immunohistochemistry staining with VHL, IMP3, S100A4, S100P. Using ROC curve analysis, threshold criteria for number of cells staining were chosen for each biomarker. Biomarkers were then evaluated as a panel for their ability to discriminate malignant from benign specimens., Results: Diagnostic sensitivity of VHL, IMP3, S100A4, and S100P were 75.0%, 79.2%, 45.8%, and 0%. When VHL, IMP3, and S100A4 were grouped into a panel, they were able to distinguish cancer from normal tissue with a sensitivity of 100% and a specificity of 96%., Conclusions: The high diagnostic value of an IHC panel consisting of VHL, IMP3, and S100A4 on surgical specimens suggests the need for future prospective studies of these biomarkers on biopsy specimens., (Copyright © 2019 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Background: Non-urothelial bladder tumors (NUBTs) are uncommon accounting for approximately 10% of the total urinary bladder tumors while 90% are urothelial in origin. There are very limited comprehensive studies on NUBTs., Aims and Objectives: The objectives of the study were to analyze the clinicopathological and immunohistochemical features of NUBTs., Materials and Methods: This is a retrospective study of NUBTs diagnosed over a period of 9 years. Patients' files were retrieved from the archives. Gross and microscopic features were recorded. Simple percentage and frequencies were used to interpret the data., Results: A total 16 cases (10.8% of all bladder tumors) of NUBT were found. Patients' ages ranged from 19 to 87 years with a male: female ratio of 4.3:1. The most common presenting symptom was gross hematuria (81.2%), and the most common location was posterolateral bladder wall. Muscle invasion was seen in 81.2% of cases, and large areas of necrosis were observed in 62.5%. There were two cases of squamous cell carcinoma, five cases each of adenocarcinoma (four secondary and one urachal) and mesenchymal tumors (four malignant and one benign), two cases of amyloid, and one case each of plasmacytomas and paraganglioma. Large areas of necrosis and muscle invasion were noted in high-grade and advanced staged tumors. In all, 43.7% had poor survival., Conclusion: NUBTs present with similar clinicoradiological findings; however, their histological features along with immunohistochemistry help in the definite diagnosis. One should be aware of these tumors as they frequently present diagnostic and therapeutic challenge. Most of these neoplasms present at an advanced stage. Large or multicentric randomized controlled studies are needed to know the exact behavior and prognosis of these tumors., Competing Interests: None