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Bladder cancer is the most common urinary tract cancer. Patients diagnosed with advanced T-stage/muscle-invasive bladder cancer through transurethral resection of bladder tumors (TURBT) are treated with total radical cystectomy; however, there is a high chance of recurrence. Nevertheless, markers for predicting this recurrence are not currently available. Here, we evaluated the chronological change of ephrin type-A receptor 2 (EPHA2) expression, a molecule known for its role in cell adhesion, to predict bladder cancer recurrence after cystectomy, using TURBT and cystectomy specimens.An immunostaining evaluation method that combines whole-slide images and image analysis software was developed to quantify and evaluate stainability objectively. We assessed the correlation between EPHA2 expression and bladder cancer recurrence using this novel immunostaining method and chronological changes in target protein expression in TURBT and radical cystectomy samples.In TURBT specimens, the number of cases with a high N-terminal/C-terminal EPHA2 ratio in the group with recurrence was significantly higher than in the non-recurrent group (p=0.019). The number of cases with a high level of C-terminal EPHA2 positivity in the radical cystectomy specimen when compared to the TURBT specimen obtained from the same patient was significantly higher in the recurrent group than in the non-recurrent group (p=0.0034).EPHA2 appears to be a promising marker for bladder tumor recurrence after cystectomy and its evaluation may enable the selection of appropriate cases for adjuvant therapy among patients undergoing radical cystectomy. Further studies, including mass-scale analysis, are required to confirm these results.

BackgroundThe active surveillance (AS) has been suggested for the initial treatment of extra-abdominal desmoid fibromatosis (EADF), the percentage of patients who shifted to invasive secondary treatments was significant. Tranilast, an anti-keloid medication, is frequently used in Japan, but there is no detailed report on its efficacy.MethodsWe retrospectively analyzed the medical records of EADF patients treated with tranilast between January 2009 and March 2021. Since EADF has been reported to shrink spontaneously, the effects of all drugs should be compared to AS. Therefore, we compared its clinical course with that under AS (determined by a systematic review) to assess the effect of tranilast. A systematic literature review of AS outcomes was conducted on July 22, 2021, according to PRISMA guidelines. The primary endpoint was the rate of conversion to secondary treatment. Secondary endpoints were progression-free survival, objective response rate (ORR), disease control rate (DCR), and adverse events. The rates of conversion to secondary treatment, ORRs, and DCRs were compared between the two groups using the Fisher's exact test.ResultsEighteen patients who received tranilast as the initial treatment for EADF were included. Two patients (11.1%) underwent surgical resection due to tumor growth and continuous pain. Compared to the secondary treatment conversion rate from the pure AS approach (40.1%), tranilast was shown to significantly reduce the rate (p = 0.01). The ORR and DCR did not different between the two groups.ConclusionsAs initial treatment for EADF, tranilast is preferred over AS.

Low-grade adenosquamous carcinoma (LGASC) is a rare type of metaplastic carcinoma of the breast (MBC) with an indolent clinical course. A few cases with high-grade transformation have been reported; however, their genetic alterations remain unclear. This study was designed to explore the somatic genetic characteristics of LGASC with transformation to high-grade MBC. Whole-genome sequencing analysis was performed on five MBCs from four patients, including one case with matching primary LGASC and lymph node metastatic tumor consisting of high-grade MBC with a predominant metaplastic squamous cell carcinoma pattern (MSC) that has progressed from LGASC, and three de novo MSC. Both LGASC and its associated MSC, unlike de novo MSC, had no TP53 mutation and tended to have fewer structural variants than de novo MSC. Both LGASC and its associated MSC had common mutations and copy number alterations, including GNAS R844C, which shows an increase in its allele frequency in MSC. These results indicated that LGASC and its associated MSC were ancestry clonal and that clonal selection occurred during progression. MSC associated with LGASC had additional pathogenic deletions of multiple tumor suppressor genes caused by, for example, SMAD4–DCC fusion. Reverse transcription polymerase chain reaction, followed by Sanger sequencing, confirmed this fusion transcript in both LGASC and its associated MSC; however, chimera proteins were not detected by Western blotting. SMAD4 protein expression had already decreased at the stage of LGASC, which may have contributed to the tumorigenesis of LGASC. In conclusion, not only LGASC but also its associated high-grade MBC may be genetically different from de novo high-grade MBC. The progression from LGASC to high-grade MBC may concern the concentration of the driver mutation caused by clonal selection and inactivation of tumor suppressor genes.

Background: Uterine adenosarcoma is a rare malignant tumor that accounts for 8% of all uterine sarcomas, and less than 0.2% of all uterine malignancies. However, it is frequently misdiagnosed in clinical examinations, including pathological diagnosis, and imaging studies owing to its rare and non-specific nature, which is further compounded by the lack of specific diagnostic markers. Case Presentation: We report a case of uterine adenosarcoma for which a comprehensive genomic profiling (CGP) test provided a chance to reach the proper diagnosis. The patient, a woman in her 60s with a history of uterine leiomyoma was diagnosed with an intra-abdominal mass post presentation with abdominal distention and loss of appetite. She was suspected to have gastrointestinal stromal tumor (GIST), and the laparotomically excised mass was found to comprise uniform spindle-shaped cells that grew in bundles with a herringbone architecture, and occasional myxomatous stroma. Immunostaining revealed no specific findings, resulting in the tumor being diagnosed as a spindle cell tumor/suspicious adult fibrosarcoma. The tumor relapsed during postoperative follow-up, and showed size reduction with chemotherapy, prior to regrowing. CGP was performed to identify a possible treatment, which resulted in detection of a JAZF1-BCORL1 rearrangement. Since the rearrangement has been reported in uterine sarcomas, we reevaluated specimens of the preceding uterine leiomyoma, which revealed the presence of adenosarcoma components in the corpus uteri. Further, both the uterine adenosarcoma and intra-abdominal mass were partially positive for CD10 and BCOR staining. Conclusions: These results conclusively identified the abdominal tumor as a metastasis of the uterine adenosarcoma. The JAZF1-BCORL1 rearrangement is predominantly associated with uterine stromal sarcomas, and ours is the second report of the same in an adenosarcoma thus far. Adenosarcomas are rare and difficult to diagnose, especially in atypical cases with scarce glandular epithelial components. Identification of rearrangements involving BCOR or BCORL1, will encourage BCOR staining analysis, thereby potentially resulting in better diagnostic outcomes. Given that platinum-based chemotherapy was proposed as the treatment choice for this patient post diagnosis with adenosarcoma, CGP also indirectly contributed to designing the best suited treatment protocol.

Objectives Molecular profiling of marker mutations has become an essential aspect in the treatment planning for colorectal cancer (CRC). Anaplastic lymphoma kinase (ALK) mutations could be used as markers in CRC molecular profiling. However, the extremely low frequency of these mutations makes their confirmation in all patients inefficient. Thus, to determine whether ALK positivity could be indicated by morphological features, we have analyzed ALK positivity in CRC tissues with a signet-ring cell carcinoma (SRCC) component. Methods We screened cases of patients who underwent CRC surgical resection at the Department of Gastrointestinal Surgery of the Kanagawa Cancer Center between January 2015 and December 2019. The selected samples were then assessed immunohistochemically using an antibody against p80 ALK. Results In total, we were able to retrieve 29 cases of CRC with the SRCC component from the database; however, 5 cases were excluded owing to the absence of formalin-fixed paraffin-embedded tissue sections or the absence of the SRCC component when the tissues were observed. In the immunohistochemical analysis, two cases showed diffused positive immunoreactivity for ALK and were defined as ALK-positive CRC. Thus, the ALK positivity rate in CRC with SRCC was determined to be 8.3%. Conclusions This present study sheds light on the morphological features of ALK-positive CRC. Our findings could contribute to the effective screening and improvement of front-line therapy for CRC.

We present the case of a 35-year-old man with intractable nausea, vomiting, and severe anemia. A computed tomography (CT) scan of the chest, abdomen, and pelvis showed a circumferential lesion thickening of up to 3.5 cm at the level of the third portion of the duodenum. No aortocaval, retroperitoneal lymphadenopathy, nor secondary lesion was observed. Esophagogastroduodenoscopy (EGD) revealed a circumferential mass within the third portion of the duodenum. Histopathology of biopsy materials from the duodenal mass showed it most likely to be a poorly differentiated adenocarcinoma. The patient underwent a subtotal stomach-preserving pancreaticoduodenectomy with regional lymph node dissection. Histologically, tumor cells with basophilic cytoplasm and pleomorphic nuclei showed a solid pattern, and expressed CD30 and SALL4 immunohistochemically, leading to a diagnosis of embryonal carcinoma-like tumor. No other primary tumor could be identified, and the location of the tumor, mainly on the mucosal surface, suggested a duodenal origin. The UICC TNM staging was T3N2M0, stage IIB. This is a rare case of primary duodenal carcinoma with features of embryonal carcinoma.

Large bone defects that occur after resection of calvarial tumours are commonly remedied using titanium meshes or bone prostheses. However, these methods have several problems. While intraoperative extracorporeal radiotherapy for bone flaps could avoid these problems, there have been only a few reports wherein meningiomas were treated with 120 Gy irradiation. Moreover, no reports are available on calvarial metastasis of sarcoma, and the therapeutic radiation dose remains uncertain. Here, we report a case of giant calvarial metastasis of myxoid liposarcoma treated with intraoperative extracorporeal radiotherapy at a dose of 50 Gy. The treatment resulted in successful tumour control followed by favourable bone reconstruction.

Mucinous cystadenocarcinoma (MCAC) with malignant ascites is rare. We report a case of a 28-year-old woman who presented with epigastric pain. The ascites in the Douglas fossa was identified at a nearby gynecology clinic. Computed tomography showed a multiloculated cystic lesion (9.5 × 6.4 cm) in the tail of the pancreas, which was diagnosed as mucinous cystic neoplasm on imaging. Staging laparoscopy was performed, and rapid cytology of ascites revealed adenocarcinoma, leading to a diagnosis of unresectable MCAC. Subsequently, combination chemotherapy with gemcitabine plus S-1 was initiated. Although there were no remarkable changes in the imaging findings, the peritoneal dissemination node was not consistently recognized in any of the imaging findings, and distal pancreatectomy was performed. A peritoneal dissemination node was not observed in the laparotomy findings, but the peritoneal lavage cytology was positive. The postoperative pathological result was non-invasive MCAC, and the ascites was suspected to be caused by cyst rupture. The patient has been recurrence-free, including the reappearance of ascites, for > 8 years after adjuvant therapy with S-1. Although careful follow-up will be required in the future, the very good prognosis in this case suggests that MCAC with malignant ascites without obvious peritoneal dissemination should be considered for surgical resection.

In prostate cancer, accurate diagnosis and grade group (GG) decision based on biopsy findings are essential for determining treatment strategies. Diagnosis by experienced urological pathologists is recommended; however, their contribution to patient benefits remains unknown. Therefore, we analyzed clinicopathological information to determine the significance of reassessment by experienced urological pathologists at a high-volume institution to identify factors involved in the agreement or disagreement of biopsy and surgical GGs. In total, 1325 prostate adenocarcinomas were analyzed, and the GG was changed in 452/1325 (34.1%) cases (359 cases were upgraded, and 93 cases were downgraded). We compared the highest GG based on biopsy specimens, with the final GG based on surgical specimens of 210 cases. The agreement rate between the surgical GG performed and assessed in our institute and the highest biopsy GG assessed by an outside pathologist was 34.8% (73/210); the agreement rate increased significantly to 50% (105/210) when biopsy specimens were reevaluated in our institute (chi-square test, P P

Differentiating small cell neuroendocrine (NE) carcinoma (SCNC) of the prostate from adenocarcinoma with NE differentiation based on morphological features alone sometimes can be challenging. Given that treatment strategies vary depending on histological type, an accurate diagnosis is critical. This study aimed to identify the accurate diagnostic factors for SCNC of the prostate. Furthermore, the possibility of novel treatment strategies through genetic analysis was also investigated. Prostate biopsies conducted in our hospital between January 2017 and May 2020 were included. Consequently, seven cases of SCNC and four cases of adenocarcinoma with NE differentiation were identified. No significant differences in the serum neuron-specific enolase, pro-gastrin-releasing peptide, and prostate-specific antigen (PSA) levels were observed between both tumors. The Ki-67 labeling index was significantly higher, and PSA immunoreactivity tended to be lower in SCNC. Although the morphology was undetectable, genetic analysis confirmed several mutations, including those of PIK3CA and TP53. The fact that morphological findings are not apparent indicates that genetic investigation rather than only morphological findings would be important in the future. In conclusion, given the heterogeneity of serum NE markers in SCNC, diagnosis based on these markers alone is challenging. A high Ki-67 labeling index and low PSA immunoreactivity may be useful for diagnosis, but p53 immunoreactivity is insufficient in distinguishing. Although further studies are required to interpret the results of the genetic analysis involving ALK, PIK3CA, and TP53 mutations, the results of our genetic analysis suggest that PIK3CA mutations in SCNC of the prostate may provide a novel therapeutic strategy.

Background: Adipocytic tumors are the most common soft tissue tumors, with lipomas and atypical lipomatous tumor/well-differentiated liposarcomas (ALT/WDL) comprising the majority of cases. Preoperative differential diagnosis of lipoma or ALT/WDL can provide important information for decisions regarding treatment. We evaluated the cytological findings of 20 cases of lipoma and ALT/WDL.Methods: Fluorescence in situ hybridization (FISH) was performed on formalin-fixed paraffin-embedded specimens (FFPE) to examine mouse double minute 2 homolog (MDM2) amplification in all cases. Tissue samples were collected from the center of the surgical materials, stained with Papanicolaou, and evaluated for 12 cytological parameters by six cytotechnologists.Results: The findings regarding large atypical cells, multinucleated cells, and nuclear pleomorphism were highly concordant among the cytotechnologists and were associated with MDM2 amplification. Large atypical cells, considered a highly specific feature of ALT/WDL, were not observed in the lipoma cases. However, the sensitivity of the large atypical cell findings was not high (67%), and therefore, comprehensive evaluation of multinucleated cells and pleomorphism is crucial for predicting the diagnosis of ALT/WDL. FISH of MDM2 on Papanicolaou-stained specimens was performed in four cases. In two cases, the results were similar to those of MDM2 FISH performed on FFPE sections and were reproducible, whereas in two other cases, the signal could not be evaluated because of the strong background coloration. Conclusions: Cytology specimens may be useful for preoperative diagnosis of adipocytic tumors, particularly if the FISH conditions for Papanicolaou-stained specimens and the detection accuracy of MDM2 amplification can be improved.

Differentiating small cell neuroendocrine carcinoma (SCNC) of the prostate from prostatic cancer with diffuse neuroendocrine (NE) differentiation based on morphological features alone can be challenging. Given that treatment strategies vary depending on histological type, accurate diagnosis is critical. This study firstly aimed to identify the accurate diagnostic factors for primary prostate NE tumors. Furthermore, the possibility of novel treatment strategies through genetic analysis is also an aim. Specifically, prostate biopsies conducted in our hospital between January 2017 and May 2020 were included. As a result seven cases of SCNC and four cases of prostatic cancer with diffuse NE differentiation were identified. No significant differences in serum neuron-specific enolase (NSE), pro-gastrin-releasing peptide (ProGRP), and prostate-specific antigen (PSA) levels were observed between SCNC and adenocarcinoma with diffuse NE differentiation. The Ki-67 labeling index was significantly higher and PSA immunoreactivity tended to be lower in SCNC. Genetic analysis did not detect any ALK mutations but confirmed several other mutations, including those of PIK3CA and TP53. In conclusion, given the heterogeneity in serum NE markers in SCNC, diagnosis based on these markers alone is difficult. A high Ki-67 labeling index and low PSA immunoreactivity may be useful for diagnosing, but p53 immunoreactivity is insufficient to distinguish these tumors. Although further studies are required to interpret the results of the genetic analysis involving ALK, PIK3CA, and TP53 mutations, the results of our genetic analysis suggest that PIK3CA mutations in SCNC of the prostate may provide a novel therapeutic strategy.

Background Fetal adenocarcinoma of the lung is a rare variant of lung adenocarcinoma and is subcategorized into low-grade and high-grade (H-FLAC) fetal adenocarcinoma. We previously reported poor prognosis in pulmonary adenocarcinomas with an H-FLAC component; however, the genetic abnormalities involved in H-FLAC remain unclear. Therefore, this study aimed to elucidate molecular abnormalities as potential therapeutic targets for H-FLACs. Methods We performed immunohistochemical analysis and comprehensive genetic analyses using whole-exome sequencing in 16 lung cancer samples with an H-FLAC component. DNA was extracted from formalin-fixed paraffin-embedded tissues after macrodissection of the H-FLAC component. Results Cancer-related mutations were identified in TP53 (7/16 cases), KMT2C (6/16 cases), KRAS (4/16 cases), NF1 (3/16 cases), STK11 (3/16 cases), CTNNB1 (2/16 cases), and EGFR (1/16 cases). A high tumor mutation burden of ≥10 mutations per megabase was observed in 3/16 cases. A high microsatellite instability was not detected in any case. Based on the cosine similarity with the Catalogue of Somatic Mutations in Cancer mutational signatures, H-FLACs were hierarchically clustered into three types: common adenocarcinoma-like (five cases), surfactant-deficient (ten cases), and signatures 2 and 13-related (one case). All common adenocarcinoma-like cases presented thyroid transcription factor-1 (TTF-1) expression, whereas surfactant-deficient cases often presented loss of TTF-1 and surfactant protein expression and included cases with mutations in the surfactant system genes NKX2-1 and SFTPC. H-FLACs displayed low programmed death ligand-1 (PD-L1) expression (1-49% of tumor cells) in 5/16 cases, and no case displayed high PD-L1 expression (≥50% of tumor cells). Conclusions This study indicates that lung cancers with an H-FLAC component rarely harbor currently targetable driver gene mutations for lung cancer but display a high frequency of KMT2C mutations. The microsatellite instability, tumor mutation burden, and PD-L1 expression status suggest a poor response to immune checkpoint therapy.

Purpose: Diagnosis of breast preneoplastic and neoplastic lesions is difficult due to their similar morphology in breast biopsy specimens. To diagnose these lesions, pathologists perform immunohistochemical analysis and consult with expert breast pathologists. These additional examinations are time-consuming and expensive. Artificial intelligence (AI)-based image analysis has recently improved, and may help in ordinal pathological diagnosis. Here, we showed the significance of machine learning-based image analysis of breast preneoplastic and neoplastic lesions for facilitating high-throughput diagnosis.Methods: Images were obtained from normal mammary glands, hyperplastic lesions, preneoplastic lesions and neoplastic lesions, such as usual ductal hyperplasia (UDH), columnar cell lesion (CCL), ductal carcinoma in situ (DCIS), and DCIS with comedo necrosis (comedo DCIS) in breast biopsy specimens. The original enhanced convoluted neural network (CNN) system was used for analyzing the pathological images. Results: The AI-based image analysis provided the following area under the curve values (AUC): normal lesion vs. DCIS, 0.9902; DCIS vs. comedo DCIS, 0.9942; normal lesion vs. CCL, 0.9786; and UDH vs. DCIS, 1.000. Multiple comparison analysis showed precision and recall scores similar to those of single comparison analysis. Based on the Gradient-weighted Class Activation Mapping (Grad-CAM) used to visualize the important regions reflecting the result of CNN analysis, the ratio of stromal tissue in the whole weighted area was significantly higher in UDH and CCL than that in DCIS. Conclusions: These analyses may provide a more accurate and rapid pathological diagnosis of patients. Moreover, Grad-CAM identifies uncharted important histological characteristics for newer pathological findings and targets of research for understanding diseases.

Diagnosis of breast preneoplastic and neoplastic lesions is difficult due to their similar morphology in breast biopsy specimens. To diagnose these lesions, pathologists perform immunohistochemical analysis and consult with expert breast pathologists. These additional examinations are time-consuming and expensive. Artificial intelligence (AI)-based image analysis has recently improved, and may help in ordinal pathological diagnosis. Here, we showed the significance of machine learning-based image analysis of breast preneoplastic and neoplastic lesions for facilitating high-throughput diagnosis. Images were obtained from normal mammary glands, hyperplastic lesions, preneoplastic lesions and neoplastic lesions, such as usual ductal hyperplasia (UDH), columnar cell lesion (CCL), ductal carcinoma in situ (DCIS), and DCIS with comedo necrosis (comedo DCIS) in breast biopsy specimens. The original enhanced convoluted neural network (CNN) system was used for analyzing the pathological images. The AI-based image analysis provided the following area under the curve values (AUC): normal lesion versus DCIS, 0.9902; DCIS versus comedo DCIS, 0.9942; normal lesion versus CCL, 0.9786; and UDH versus DCIS, 1.000. Multiple comparison analysis showed precision and recall scores similar to those of single comparison analysis. Based on the gradient-weighted class activation mapping (Grad-CAM) used to visualize the important regions reflecting the result of CNN analysis, the ratio of stromal tissue in the whole weighted area was significantly higher in UDH and CCL than that in DCIS. These analyses may provide a more accurate and rapid pathological diagnosis of patients. Moreover, Grad-CAM identifies uncharted important histological characteristics for newer pathological findings and targets of research for understanding diseases.

Background Neuroendocrine carcinoma (NEC) originating from the extrahepatic bile duct (EHBD) is very rare but is known for its aggressiveness and poor prognosis. We herein report a case of rapidly progressed NEC in the extrahepatic bile duct. Case presentation An 84-year-old man was referred to our facility with obstructive jaundice and abdominal pain. Imaging studies revealed an irregular filling defect in the middle bile duct by endoscopic retrograde cholangiopancreatography and an enhanced wall thickening from the middle to distal portion by enhanced computed tomography. The patient was initially diagnosed with extrahepatic cholangiocarcinoma by a bile duct biopsy and underwent pancreatoduodenectomy with lymph node dissection. The pathological findings showed an NEC with an adenosquamous carcinoma component in the extrahepatic bile duct with lymph node metastases. The patient experienced multiple liver metastases 1 month after surgery and died 3 months after surgery. Due to the rapid progression of his disease, his general condition deteriorated, and he was unable to receive any additional treatments, such as chemotherapy. Conclusion As shown in our case, NEC of the EHBD has an extremely poor prognosis and can sometimes progress rapidly. Multimodality treatment should be considered, even in cases of locoregional disease.

A 55-year-old man was admitted to our hospital for examination and treatment of a transverse colon tumor detected at a nearby hospital. After CT, FDG-PET, and laparotomy biopsy, he was diagnosed with neuroendocrine cancer(Ki-67 index 40%)without distant metastasis. He underwent transverse colectomy. The pathological diagnosis was transverse colon neuroendocrine cancer(Ki-67 index 24.7%). Six courses of carboplatin and etoposide therapy as adjuvant chemotherapy were administered. Seven months after surgery, he developed lung metastasis that was surgically removed by partial lung resection. Eighteen months after the initial surgery, liver metastasis developed in S5 and S8. A right hepatic lobectomy was performed and there has been no recurrence after hepatectomy. The patient remains alive at 3 years and 4 months after initial treatment.

It currently remains unclear whether tumor spread through airspaces (STAS) actually exist in vivo or are an artifact. The morphologies of STAS and tumor cell clusters in airway secretions collected from the segmental or lobar bronchus of resected lung adenocarcinomas and squamous cell carcinomas were compared among 48 patients. The EGFR status of tumor cell clusters in airway secretions was also compared with that of the main tumor in EGFR mutant adenocarcinomas. Tumor cell clusters were observed in the airway secretion cytology of ten patients (20.8%), and eight patients were adenocarcinoma (20.0% of adenocarcinoma). The morphology of STAS closely resembled that of tumor cell clusters detected in airway secretion cytology. The positive rates of airway secretion cytology were 83.3%, 100%, and 50% in papillary adenocarcinoma, micropapillary adenocarcinoma, and invasive mucinous adenocarcinoma, respectively. Among three EGFR mutant adenocarcinomas, the EGFR mutation subtypes of the main tumors in FFPE sections and tumor cell clusters in airway secretions were identical. These indicate that STAS may be detected in the airway secretion cytology. STAS is common in papillary or micropapillary adenocarcinoma and may spread as far as the segmental or lobar bronchus at the time of surgery.

A 41-year-old female smoker presented with a vaginal mass. Gynecological examination showed a mass filling the uterine corpus, cervix, and vagina. A total abdominal hysterectomy was performed. Macroscopic findings included a large fragile mass involving the uterine cavity, cervix, and vagina. Histology revealed atypical ducts admixed with solid components consisting of large atypical cells. The initial pathological diagnosis was grade 3 endometrioid adenocarcinoma. The patient was designated as stage II according to the 2008 International Federation of Gynecology and Obstetrics (FIGO) staging. Two years later, two nodules were found in the upper lobe of the left lung, and the patient underwent an upper lobectomy. The masses, which exhibited solid and organoid growth patterns of large atypical cells, had histological characteristics of large cell neuroendocrine carcinoma (LCNEC) of the lung. However, the tumor was immunohistochemically positive for neuroendocrine markers, such as synaptophysin in addition to estrogen receptor and progesterone receptor, and the tumor was negative for thyroid transcription factor-1. These immunohistochemical results were almost identical to those of the solid portions of the uterine carcinoma. The final diagnosis was LCNEC combined with endometrioid adenocarcinoma of the uterine corpus and lung metastasis of the LCNEC component of the endometrial carcinoma. LCNEC often arises in the lung, but it rarely arises in other organs. Some patients with metastatic components exhibited only a LCNEC pattern although the primary tumor was a mixed carcinoma consisting of LCNEC and other histology, like the present case. LCNEC is often poorly differentiated, especially in extrapulmonary primary organ LCNEC. Therefore, pathologists should consider metastatic carcinoma when they encounter lung LCNEC in a patient with a preceding extrapulmonary carcinoma composed of a poorly differentiated component or LCNEC component, and they should clarify tumor immunohistochemical characteristics to confirm the diagnosis.

Gangliocytic paraganglioma (GP) has been regarded as a rare benign tumor that commonly arises from the second part of the duodenum. As GP does not exhibit either prominent mitotic activity or Ki-67 immunoreactivity, it is often misdiagnosed as neuroendocrine tumor (NET) G1. However, the prognosis might be better in patients with GP than in those with NET G1. Therefore, it is important to differentiate GP from NET G1. Moreover, our previous study indicated that GP accounts for a substantial, constant percentage of duodenal NETs. In the present article, we describe up-to-date data on the clinicopathological characteristics of GP and on the immunohistochemical findings that can help differentiate GP from NET G1, as largely revealed in our new and larger literature survey and recent multi-institutional retrospective study. Furthermore, we would like to refer to differential diagnosis and clinical management of this tumor and provide intriguing information about the risk factors for lymph node metastasis on GP.

Background: Although gangliocytic paraganglioma (GP) is considered a rare benign neuroendocrine tumor, cases of mortality have been reported. Occasionally, GP is misdiagnosed as neuroendocrine tumor G1, which is associated with a poorer prognosis than GP. To avoid such misdiagnoses, it is important to understand the clinicopathological characteristics of GP. Thus, herein, we discuss the current literature on the clinicopathological characteristics of GP. Methods: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. PubMed and Japana Centra Revuo Medicina searches were used to identify papers describing GP. Inclusion criteria included confirmation of epithelioid, spindle-shaped, and ganglion-like cells in the main article and/or figures and whether the paper was cited in other studies of GP. Data were collected on age, sex, site of the primary lesion, tumor size, treatment, prognosis, lymph node metastasis (LNM), depth of tumor invasion, rate of preoperative diagnosis, and clinical symptoms. Results: In total, 162 papers containing 263 cases of GP met the criteria. The mean age at diagnosis was 53.5 years. The male-to-female ratio was 157:104. The mean tumor size was 25.7 mm. The predominant site of the primary tumor was the duodenum (89.7%). The most common clinical sign of GP was gastrointestinal bleeding (47.9%). Other signs and symptoms of GP included abdominal pain (44.7%), anemia (20.3%), incidental findings (12.9%), nausea (6.9%), weight loss (5.5%), general fatigue (5.1%), jaundice (4.6%), and incidental autopsy findings (5.1%). LNM was observed in 11.4% of patients. Liver metastasis was observed in 1.1% of patients. Depth of tumor invasion (penetrating beyond the submucosal layer or sphincter of Oddi) was by far the most significant risk factor for LNM in patients with GP. This suggests, along with histological heterogeneity, that GP may have hamartomatous characteristics. Furthermore, immunohistochemical expression of progesterone receptor and pancreatic polypeptide were useful in distinguishing between GP and neuroendocrine tumor G1, even in small biopsy specimens. Conclusions: We reveal the clinicopathological characteristics of GP, including risk factors for LNM, differential diagnostic approaches, and improvements in the clinical management of this tumor.In addition, GP may have hamartomatous characteristics.

Fetal adenocarcinoma is a rare variant of lung adenocarcinoma, which is subcategorized into low-grade and high-grade forms. High-grade fetal adenocarcinoma confers worse prognosis than low-grade fetal adenocarcinoma, but the prognostic differences between high-grade fetal adenocarcinoma and conventional lung adenocarcinoma are unknown. We reviewed tissue sections of 3719 cases of surgically resected primary lung cancers and found 53 lung cancers with a high-grade fetal adenocarcinoma component. We analyzed their clinicopathological and immunohistochemical features, and performed a prognostic analysis of adenocarcinomas with the fetal-type component. We further analyzed the prognostic differences between adenocarcinomas with the fetal-type component and conventional adenocarcinomas without the fetal-type component. Lung cancers with the fetal-type component predominantly occurred in elderly men with a smoking history. Twenty-nine patients had stage I disease, 13 patients had stage II, and 11 patients had stage III. The fetal-type histology was combined with conventional-type adenocarcinoma (41 cases), squamous cell carcinoma (5 cases), large cell neuroendocrine carcinoma (5 cases), enteric adenocarcinoma (2 cases), and small cell carcinoma (1 case). The fetal-type component showed immunopositivity for α-fetoprotein (39%), glypican-3 (37%), and SALL4 (17%). The 5-year overall survivals of fetal-type-predominant and fetal-type-nonpredominant patients were 44 and 56%, respectively (P = 0.962). The 5-year overall survivals of lepidic-, acinar-, papillary-, solid-, and micropapillary-predominant adenocarcinomas, invasive mucinous adenocarcinomas, and adenocarcinomas with the fetal-type component were 94, 82, 77, 69, 57, 83, and 41%, respectively (P

Background The worldwide incidence of neuroendocrine tumors (NETs) has increased remarkably, with the hindgut being the second most common site for such tumors. However, the mechanisms underlying progression and metastasis of hindgut NETs are unclear. A retrospective study was conducted to elucidate these mechanisms. Methods Clinicopathological data of cases of hindgut NET between April 1996 and September 2015 were analyzed, retrospectively. Patients with neuroendocrine carcinoma were excluded. Formalin-fixed paraffin-embedded tissues of hindgut NET cases were subjected to detailed morphometric and immunohistochemical analyses. Statistical analyses were performed using the non-parametric Mann-Whitney U test, Spearman’s correlation coefficient, and chi-squared test. Multivariate logistic regression analysis was conducted as appropriate for the data set. Results Fifty-six hindgut NET cases were considered. Microvessel density and lymphatic microvessel density were identified as significant risk factors for venous and lymphatic invasion. There was a positive correlation between microvessel density and the maximum tumor diameter. Multivariate logistic regression analysis revealed that the maximum tumor diameter alone was an independent predictor of lymph node metastasis, whereas lymphovascular invasion and MVD was not the predictor of lymph node metastasis. There were no significant correlations between the Ki-67 labeling index and any of the parameters evaluated including age, sex, the maximum tumor diameter, venous invasion, lymphatic invasion, microvessel density, lymphatic microvessel density, and lymph node metastasis. Conclusions Angiogenic mechanisms may play important roles in the progression of hindgut NET. Otherwise, the maximum tumor diameter alone was an independent predictor of lymph node metastasis in hindgut NETs. Moreover, our study raises the question of whether the presence of lymphovascular invasion, in endoscopically obtained hindgut NET tissues, is an absolute indication for additional surgery or not.

The absence of highly specific markers for malignant mesothelioma (MM) has served an obstacle for its diagnosis and development of molecular-targeting therapy against MM. Here, we show that a novel mucin-like membrane protein, sialylated protein HEG homolog 1 (HEG1), is a highly specific marker for MM. A monoclonal antibody against sialylated HEG1, SKM9-2, can detect even sarcomatoid and desmoplastic MM. The specificity and sensitivity of SKM9-2 to MM reached 99% and 92%, respectively; this antibody did not react with normal tissues. This accurate discrimination by SKM9-2 was due to the recognition of a sialylated O-linked glycan with HEG1 peptide. We also found that gene silencing of HEG1 significantly suppressed the survival and proliferation of mesothelioma cells; this result suggests that HEG1 may be a worthwhile target for function-inhibition drugs. Taken together, our results indicate that sialylated HEG1 may be useful as a diagnostic and therapeutic target for MM.

It currently remains unclear whether tumor spread through airspaces (STAS) actually exist in vivo or are an artifact. The morphologies of STAS and tumor cell clusters in airway secretions collected from the segmental or lobar bronchus of resected lung adenocarcinomas and squamous cell carcinomas were compared among 48 patients. The EGFR status of tumor cell clusters in airway secretions was also compared with that of the main tumor in EGFR mutant adenocarcinomas. Tumor cell clusters were observed in the airway secretion cytology of ten patients (20.8%), and eight patients were adenocarcinoma (20.0% of adenocarcinoma). The morphology of STAS closely resembled that of tumor cell clusters detected in airway secretion cytology. The positive rates of airway secretion cytology were 83.3%, 100%, and 50% in papillary adenocarcinoma, micropapillary adenocarcinoma, and invasive mucinous adenocarcinoma, respectively. Among three EGFR mutant adenocarcinomas, the EGFR mutation subtypes of the main tumors in FFPE sections and tumor cell clusters in airway secretions were identical. These indicate that STAS may be detected in the airway secretion cytology. STAS is common in papillary or micropapillary adenocarcinoma and may spread as far as the segmental or lobar bronchus at the time of surgery.

Inflammatory myofibroblastic tumor(IMT)is a rare neoplasm. IMTs are found in a number of locations throughout the body, but splenic involvement is uncommon. One case of splenic IMT is described. A 42-year-old woman presented with anterior chest pain and was found to have a splenic mass by computed tomography(CT). Fluorine-18-FDG-PET showed no FDG accumulation in the spleen. Magnetic resonance imaging(MRI)at 6 months follow-up showed an increase in the size of the tumor. We performed splenectomy for a suspected malignant tumor. The surgical specimen was a gray-white mass in the spleen. The mass was histopathologically diagnosed as primary splenic IMT because it consisted of desmin- and SMA-positive spindle-shaped cells with various inflammatory cells. In Japan, only 6 cases(including this case)of primary splenic IMT have been reported. Surgery is the only curative approach, but recurrences occur in around 5% of cases of pulmonary IMT, and around 25% of cases of extrapulmonary IMT. This patient needs to be carefully followed up.