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Objectives Mesothelioma is a lethal disease that arises from the serosal lining of organ cavities. Several recurrent alterations have been observed in pleural and peritoneal ­mesotheliomas, including in BAP1, NF2, and CDKN2A. Although specific histopathologic parameters have been correlated with prognosis, it is not as well known whether genetic alterations correlate with histologic findings. Methods We reviewed 131 mesotheliomas that had undergone next-generation sequencing (NGS) at our institutions after pathologic diagnosis. There were 109 epithelioid mesotheliomas, 18 biphasic mesotheliomas, and 4 sarcomatoid mesotheliomas. All our biphasic and sarcomatoid cases arose in the pleura. Of the epithelioid mesotheliomas, 73 were from the pleura and 36 were from the peritoneum. On average, patients were 66 years of age (range, 26-90 years) and predominantly male (92 men, 39 women). Results The most common alterations identified were in BAP1, CDKN2A, NF2, and TP53. Twelve mesotheliomas did not show a pathogenic alteration on NGS. For epithelioid mesotheliomas in the pleura, the presence of an alteration in BAP1 correlated with low nuclear grade (P = .04), but no correlation was found in the peritoneum (P = .62). Similarly, there was no correlation between the amount of solid architecture in epithelioid mesotheliomas and any alterations in the pleura (P = .55) or peritoneum (P = .13). For biphasic mesotheliomas, cases with either no alteration detected or with an alteration in BAP1 were more likely to be epithelioid predominant (>50% of the tumor, P = .0001), and biphasic mesotheliomas with other alterations detected and no alteration in BAP1 were more likely to be sarcomatoid predominant (>50% of the tumor, P = .0001). Conclusions This study demonstrates a significant association between morphologic features associated with a better prognosis and an alteration in BAP1.

PURPOSE: The lack of effective molecular biomarkers to monitor idiopathic pulmonary fibrosis (IPF) activity or treatment response remains an unmet clinical need. Herein, we determined the utility of fibroblast activation protein inhibitor for positron emission tomography (FAPI PET) imaging in a mouse model of pulmonary fibrosis. METHODS: Pulmonary fibrosis was induced by intratracheal administration of bleomycin (1 U/kg) while intratracheal saline was administered to control mice. Subgroups from each cohort (n=3–5) underwent dynamic 1 h PET/CT after intravenously injecting FAPI-46 radiolabeled with gallium-68 ([(68)Ga]Ga-FAPI-46) at 7 d and 14 d following disease induction. Animals were sacrificed following imaging for ex vivo gamma counting and histologic correlation. [(68)Ga]Ga-FAPI-46 uptake was quantified and reported as percent injected activity per cc (%IA/cc) or percent injected activity (%IA). Lung CT density in Hounsfield units (HU) was also correlated with histologic examinations of lung fibrosis. RESULTS: CT only detected differences in the fibrotic response at 14 d post-bleomycin administration. [(68)Ga]Ga-FAPI-46 lung uptake was significantly higher in the bleomycin group than in control subjects at 7 d and 14 d. Significantly (P=0.0012) increased [(68)Ga]Ga-FAPI-46 lung uptake in the bleomycin groups at 14 d (1.01±0.12 %IA/cc) vs. 7 d (0.33±0.09 %IA/cc) at 60 min post-injection of the tracer was observed. These findings were consistent with an increase in both fibrinogenesis and FAP expression as seen in histology. CONCLUSION: CT was unable to assess disease activity in a murine model of IPF. Conversely, FAPI PET detected both the presence and activity of lung fibrogenesis, making it a promising tool for assessing early disease activity and evaluating the efficacy of therapeutic interventions in lung fibrosis patients.

Lung transplantation has been well described for COVID-19 patients in the acute setting, but less so for the resulting pulmonary sequelae. We share one of the first cases of lung transplantation for post COVID-19 pulmonary fibrosis. A 52-year-old female developed COVID-19 in July 2020 and mounted a partial recovery, but went on to have declining function over the ensuing three months and developed fibrocystic lung changes. She underwent bilateral lung transplantation and recovered rapidly, was discharged home POD 14, and has done well in follow-up. We demonstrate that lung transplantation is an acceptable therapy to treat post COVID-19 pulmonary fibrosis.

The Cancer Genome Atlas (TCGA) is one of the largest biorepositories of digital histology. Deep learning (DL) models have been trained on TCGA to predict numerous features directly from histology, including survival, gene expression patterns, and driver mutations. However, we demonstrate that these features vary substantially across tissue submitting sites in TCGA for over 3,000 patients with six cancer subtypes. Additionally, we show that histologic image differences between submitting sites can easily be identified with DL. Site detection remains possible despite commonly used color normalization and augmentation methods, and we quantify the image characteristics constituting this site-specific digital histology signature. We demonstrate that these site-specific signatures lead to biased accuracy for prediction of features including survival, genomic mutations, and tumor stage. Furthermore, ethnicity can also be inferred from site-specific signatures, which must be accounted for to ensure equitable application of DL. These site-specific signatures can lead to overoptimistic estimates of model performance, and we propose a quadratic programming method that abrogates this bias by ensuring models are not trained and validated on samples from the same site., Deep learning models have been trained on The Cancer Genome Atlas to predict numerous features directly from histology, including survival, gene expression patterns, and driver mutations. Here, the authors demonstrate that site-specific histologic signatures can lead to biased estimates of accuracy for such models, and propose a method to minimize such bias.

In the third year of the SARS-CoV-2 pandemic, much has been learned about the long- term effect of COVID-19 pneumonia on the lungs. Approximately one-third of patients with moderate-to-severe pneumonia, especially those requiring intensive care therapy or mechanical ventilation, have residual abnormalities on chest CT one year after presentation. Abnormalities range from parenchymal bands to bronchial dilation to frank fibrosis. Less is known about the long-term pulmonary vascular sequelae, but there appears to be a persistent, increased risk of venothromboembolic events in a small cohort of patients. Finally, the associated histologic abnormalities resulting from SARS- CoV-2 infection are similar to those of patients with other causes of acute lung injury.

Malignant peritoneal mesothelioma historically carried a grim prognosis, but outcomes have improved substantially in recent decades. The prognostic significance of clinical, morphologic, and immunophenotypic features remains ill-defined. This multi-institutional cohort comprises 225 malignant peritoneal mesotheliomas, which were assessed for 21 clinical, morphologic, and immunohistochemical parameters. For epithelioid mesotheliomas, combining nuclear pleomorphism and mitotic index yielded a composite nuclear grade, using a previously standardized grading system. Correlation of clinical, morphologic, and immunohistochemical parameters with overall and disease-free survival was examined by univariate and multivariate analyses. On univariate analysis, longer overall survival was significantly associated with diagnosis after 2000 (P = 0.0001), age

Patients with connective tissue diseases may have pulmonary involvement, including interstitial lung disease. Various patterns of interstitial lung disease have been classically described in certain connective tissue diseases. It is now recognized that there is significant overlap between patterns of interstitial lung disease observed in the various connective tissue diseases. Differentiating idiopathic from connective tissue disease-related interstitial lung disease is challenging but of clinical importance. New concepts in the diagnosis of connective tissue disease related interstitial lung disease may prove useful in making the diagnosis.

Immunohistochemistry plays an indispensable role in accurate diagnosis of malignant mesothelioma, particularly in morphologically challenging cases and in biopsy and cytology specimens, where tumor architecture is difficult or impossible to evaluate. Application of a targeted panel of mesothelial- and epithelial-specific markers permits correct identification of tumor lineage in the vast majority of cases. An immunopanel including two mesothelial markers (calretinin, CK5/6, WT-1, or D2-40) and two epithelial markers (MOC-31 and claudin-4) offers good sensitivity and specificity, with adjustments as appropriate for the differential diagnosis. Once mesothelial lineage is established, malignancy-specific studies can help verify a diagnosis of malignant mesothelioma. BAP1 loss, CDKN2A homozygous deletion, and MTAP loss are highly specific markers of malignancy in a mesothelial lesion, and they attain acceptable diagnostic sensitivity when applied as a diagnostic panel. Novel markers of malignancy, such as 5-hmC loss and increased EZH2 expression, are promising, but have not yet achieved widespread clinical adoption. Some diagnostic markers also have prognostic significance, and PD-L1 immunohistochemistry may predict tumor response to immunotherapy. Application and interpretation of these immnuomarkers should always be guided by clinical history, radiographic findings, and above all histomorphology.

Ancillary studies facilitate accurate diagnosis of morphologically challenging mesothelial proliferations. The current diagnostic algorithm proceeds from BAP1 immunohistochemistry to CDKN2A fluorescence in situ hybridization. While MTAP immunohistochemistry has recently shown promise as a surrogate for CDKN2A fluorescence in situ hybridization, it has been examined in only a few single-institution studies. Furthermore, there are no published reports on interobserver agreement or interlaboratory reproducibility for MTAP immunohistochemistry. We performed MTAP immunohistochemistry on 20 benign mesothelial lesions and 99 malignant mesotheliomas from five mesothelioma centers in four countries, and each MTAP stain was independently interpreted by four pathologists. CDKN2A fluorescence in situ hybridization data were available for a subset of cases, and a subset of cases was subjected in MTAP immunohistochemistry in multiple laboratories to assess interlaboratory reproducibility. Interobserver agreement in MTAP immunostain interpretation was excellent for all mesothelial lesions (kappa: 0.85) and for malignant mesothelioma cases only (kappa: 0.82). Interlaboratory reproducibility was also excellent (kappa values for paired protocols: 0.77–0.89). MTAP loss by immunohistochemistry was 78% sensitive and 96% specific for CDKN2A homozygous deletion. MTAP immunohistochemistry is a reliable surrogate for CDKN2A fluorescence in situ hybridization in diagnosis of malignant mesothelioma. Interobserver agreement is excellent for interpretation of MTAP staining, and protocols performed in different laboratories yield concordant MTAP staining results. Rare cases with immunohistochemical MTAP loss may retain normal CDKN2A copy number, and the MTAP staining results should be correlated with clinicopathologic findings and other ancillary studies.

RationaleContribution of central lung tissues to pathogenesis of idiopathic pulmonary fibrosis (IPF) remains unknown.ObjectiveTo ascertain the relationship between cell types of IPF-central and IPF-peripheral lung explants using RNA sequencing (RNA-seq) transcriptome.MethodsBiopsies of paired IPF-central and IPF-peripheral along with non-IPF lungs were selected by reviewing H&E data. Criteria for differentially expressed genes (DEG) were set at false discovery rate 2. Computational cell composition deconvolution was performed. Signature scores were computed for each cell type.FindingsComparison of central IPF versus non-IPF identified 1723 DEG (1522 upregulated and 201 downregulated). Sixty-two per cent (938/1522) of the mutually upregulated genes in central IPF genes were also upregulated in peripheral IPF versus non-IPF. Moreover, 85 IPF central-associated genes (CAG) were upregulated in central IPF versus both peripheral IPF and central non-IPF. IPF single-cell RNA-seq analysis revealed the highest CAG signature score in myofibroblasts and significantly correlated with a previously published activated fibroblasts signature (r=0.88, p=1.6×10−4). CAG signature scores were significantly higher in IPF than in non-IPF myofibroblasts (p=0.013). Network analysis of central-IPF genes identified a module significantly correlated with the deconvoluted proportion of myofibroblasts in central IPF and anti-correlated with inflammation foci trait in peripheral IPF. The module genes were over-represented in idiopathic pulmonary fibrosis signalling pathways.InterpretationGene expression in central IPF lung regions demonstrates active myofibroblast features that contributes to disease progression. Further elucidation of pathological transcriptomic state of cells in the central regions of the IPF lung that are relatively spared from morphological rearrangements may provide insights into molecular changes in the IPF progression.

Programmed death-ligand 1 (PD-L1) expression has been described in patients with malignant peritoneal mesothelioma (MPM), but treatment strategies utilising immune checkpoint inhibition are yet to be defined. Here, we examine levels of PD-L1 expression in MPM patients treated with systemic and/or intraperitoneal chemotherapy using tissue from patient tumour biopsies or resections at multiple time points. We found the mean PD-L1 expression was higher in those with a germline mutation and/or those with a higher somatic mutation burden. Moreover, PD-L1 expression was lower in patients who had received prior chemotherapy as compared to the treatment-naive cohort. Twenty patients who received chemotherapy, either systemic and/or peritoneal, between PD-L1 measurements showed marked heterogeneity. Six (30%) patients demonstrated upregulation of PD-L1, while eight (40%) demonstrated downregulation. Heterogeneity in PD-L1 expression in MPM before and after cytotoxic therapies may present an additional consideration when initiating immune checkpoint inhibition in this rare and challenging disease.

Objectives Numerous studies on malignant mesothelioma (MM) highlight the prognostic importance of histologic subtype, nuclear grade, and necrosis. This study compares these parameters in paired biopsy and resection specimens of pleural MM. Methods Histologic subtype, percentage of epithelioid morphology, nuclear grade, and the presence or absence of necrosis were compared in 429 paired biopsies and resection specimens of pleural MM from 19 institutions. Results Histologic subtype was concordant in 81% of cases (κ = 0.58). When compared with resection specimens, epithelioid morphology at biopsy had a positive predictive value (PPV) of 78.9% and a negative predictive value (NPV) of 93.5%; sarcomatoid morphology showed high PPV (92.9%) and NPV (99.3%), and biphasic morphology PPV was 89.7% and NPV was 79.7%. Agreement of the percentage of epithelioid morphology was fair (κ = 0.27). Nuclear grade and necrosis were concordant in 75% (κ = 0.59) and 81% (κ = 0.53) of cases, respectively. Nuclear grade showed moderate (κ = 0.53) and substantial (κ = 0.67) agreement from patients with and without neoadjuvant therapy, respectively, and necrosis showed moderate (κ = 0.47 and κ = 0.60) agreement, respectively, in the same subsets of paired specimens. Conclusions Paired biopsy-resection specimens from pleural MM show overall moderate agreement in pathologic parameters. These findings may help guide postbiopsy management and triage of patients with MM.

Objectives To present an index case and review the histologic and electron microscopic findings in chloroquine (CQ) and hydroxychloroquine (HCQ) myopathy, focusing primarily on cardiomyopathy. CQ and HCQ are antimalarial drugs with disease-modifying activity in rheumatic diseases (DMARD) and now are among the most widely used DMARDs. Although they are rare, severe adverse effects caused mainly by deposition of intracellular metabolites in both cardiac and skeletal muscle have been described. Currently, both CQ and HCQ have been proposed to have efficacy for patients with coronavirus disease 2019, and several large centers in the United States and other countries have started clinical trials. Methods A case of HCQ cardiotoxicity diagnosed on an endomyocardial biopsy is presented. A review of the pathology archives was performed to identify additional cases of CQ or HCQ myopathy, and histologic changes were recorded. A brief literature review with an emphasis on pathologic findings in myopathies was performed. Results Including the index case, 4 cases of CQ or HCQ myopathy were identified. Light microscopic findings included vacuolated myopathy, and electron microscopic findings included myeloid bodies and curvilinear inclusion bodies. Conclusion CQ and HCQ myopathy can present following long-term administration of the drug. The pathologic findings are nonspecific and overlap with other vacuolated myopathies, necessitating careful correlation of the histologic changes with the patient’s medical history.

The Cancer Genome Atlas (TCGA) is one of the largest biorepositories of digital histology. Deep learning (DL) models have been trained on TCGA to predict numerous features directly from histology, including survival, gene expression patterns, and driver mutations. However, we demonstrate that these features vary substantially across tissue submitting sites in TCGA for over 3,000 patients with six cancer subtypes. Additionally, we show that histologic image differences between submitting sites can easily be identified with DL. This site detection remains possible despite commonly used color normalization and augmentation methods, and we quantify the digital image characteristics constituting this histologic batch effect. As an example, we show that patient ethnicity within the TCGA breast cancer cohort can be inferred from histology due to site-level batch effect, which must be accounted for to ensure equitable application of DL. Batch effect also leads to overoptimistic estimates of model performance, and we propose a quadratic programming method to guide validation that abrogates this bias.

Molecular alterations in cancer can cause phenotypic changes in tumor cells and their microenvironment. Routine histopathology tissue slides, which are ubiquitously available, can reflect such morphological changes. Here, we show that deep learning can consistently infer a wide range of genetic mutations, molecular tumor subtypes, gene expression signatures and standard pathology biomarkers directly from routine histology. We developed, optimized, validated and publicly released a one-stop-shop workflow and applied it to tissue slides of more than 5,000 patients across multiple solid tumors. Our findings show that a single deep learning algorithm can be trained to predict a wide range of molecular alterations from routine, paraffin-embedded histology slides stained with hematoxylin and eosin. These predictions generalize to other populations and are spatially resolved. Our method can be implemented on mobile hardware, potentially enabling point-of-care diagnostics for personalized cancer treatment. More generally, this approach could elucidate and quantify genotype-phenotype links in cancer. Two papers by Kather and colleagues and Gerstung and colleagues develop workflows to predict a wide range of molecular alterations from pan-cancer digital pathology slides.

Malignant mesothelioma is an uncommon tumor that may be difficult to diagnose. The International Mesothelioma Interest Group has been writing guidelines for pathological diagnosis that are periodically updated. The guidelines are being updated based on published literature in the last 3 years, and experience of more than 20 leading international pathologists in the field who will be co-authors. Updates were discussed by attendees of the Pulmonary Pathology Society Biennial Meeting (Dubrovnik, Croatia, June 2019). Areas with significant advancements/changes include utilization of immunohistochemistry (establishing mesothelial lineage and benign versus malignant), prognosis and nuclear grading, biphasic malignant mesothelioma, transitional pattern, malignant mesothelioma in situ, and therapeutic/molecular targets.

Opsoclonus myoclonus syndrome (OMS) is a rare neurological syndrome caused by a paraneoplastic autoimmune process that affects children with neuroblastic tumors. Treatment includes corticosteroids, intravenous gamma globulin (IVIG), rituximab, and other immunosuppressive therapies. Here, we describe a patient diagnosed with OMS associated with a localized inflammatory myofibroblastic tumor. The patient has no evidence of tumor recurrence following surgical resection with 8-month follow-up. The neurologic symptoms resolved with corticosteroids and IVIG. This case demonstrates that in children, neoplasms other than neuroblastoma may be associated with this paraneoplastic syndrome, and highlights the importance of evaluating patients with OMS for underlying malignancies.

Mesothelioma is a rare malignant tumor of the serosal membranes that can be challenging to diagnose, especially on small biopsy specimens. There are updated guidelines on the diagnosis and classification of mesothelioma, which incorporate advancements in understanding mesothelioma biology published in the literature over recent years. This review will discuss marked developments and/or improvements that have been made, including: (1) to the histologic classifications of mesothelioma; (2) the use of such classifications and nuclear grading in prognosis; (3) the indispensability of ancillary studies in the diagnosis of mesothelioma; (4) the application of these pleural based classifications and diagnostic schemes in peritoneal mesothelioma; and (5) the potential for diagnosis of mesothelioma in situ.

Kikuchi–Fujimoto's disease (KFD), alternatively termed histiocytic necrotizing lymphadenitis, was first described in 1972. KFD is rare in children, with most of the cases occurring between the ages of 20 and 30 years with a female-to-male ratio of 4:1. The etiology is unknown, although infectious and autoimmune mechanisms have been proposed. KFD manifests with a spectrum of nonspecific clinical symptoms and laboratory findings. KFD is without a definitive diagnostic test and is a diagnosis of exclusion, which must be differentiated from other disease processes with associated lymphadenopathy. Significant overlap in both clinical presentation and histological features with other diseases, such as non-Hodgkin lymphoma, systemic lupus erythematosus, and active tuberculosis (TB), presents challenges in diagnosis. A small number of case reports have been published describing the coexistence of KFD and active TB. Most reported cases occur in TB endemic areas. In the largest analysis of KFD, TB infection was concurrent in 2% of cases. Most of the cases occurred in adult patients. To our knowledge, there have been no pediatric cases of KFD with concurrent TB infection reported in the United States. This study describes a case of KFD with concurrent Mycobacterium tuberculosis infection in a young male from the United States.

Laryngotracheal amyloid deposition is an uncommon manifestation of systemic light chain amyloidosis. Diagnostic imaging, such as CT, is useful for suggesting the possibility of amyloidosis and delineating the extent of the lesions for surgical management; however, the diagnosis is confirmed with the histologic finding of amorphous eosinophilic material which stains positively for Congo red and may show apple green birefringence on polarization. These features are exemplified in this sine qua non radiology-pathology correlation article.

High-grade conventional osteosarcoma of the mandible is a rare entity that can manifest as a rapidly growing mass. The authors report the case of a young adult patient with right mandible pain and swelling and a history of humeral osteosarcoma treated over 1 decade earlier. Computed tomography and magnetic resonance imaging showed a mass arising from the right mandible that progressed despite induction chemotherapy and the patient underwent surgery. Histopathology revealed the presence of malignant osteoblasts and osteoid, which led to the diagnosis of high-grade conventional osteosarcoma. There were also regional lymph node metastases. Genetic testing revealed a p53 germline mutation. The presence of mandibular osteosarcoma in a young patient should raise the suspicion of an underlying p53 germline mutation. Ultimately, the recurrent tumor regressed with Etoposide and Ifosfamide.

Precision treatment of cancer relies on genetic alterations which are diagnosed by molecular biology assays.1 These tests can be a bottleneck in oncology workflows because of high turnaround time, tissue usage and costs.2 Here, we show that deep learning can predict point mutations, molecular tumor subtypes and immune-related gene expression signatures3,4 directly from routine histological images of tumor tissue. We developed and systematically optimized a one-stop-shop workflow and applied it to more than 4000 patients with breast5, colon and rectal6, head and neck7, lung8,9, pancreatic10, prostate11 cancer, melanoma12 and gastric13 cancer. Together, our findings show that a single deep learning algorithm can predict clinically actionable alterations from routine histology data. Our method can be implemented on mobile hardware14, potentially enabling point-of-care diagnostics for personalized cancer treatment in individual patients.

We present a case of a neonate with tracheoesophageal fistula and esophageal atresia along with a suspicious lung mass who had a false-positive newborn screen for cystic fibrosis due to an elevated serum immunoreactive trypsinogen with an additionally elevated serum lipase. The infant’s lung mass was found to contain heterotopic pancreatic tissue consisting of acini, ducts, and islet cells, without an associated gastrointestinal duplication cyst. This constellation of congenital abnormalities has not been described in previous literature. Also, this is the first reported case of a neonate with elevated serum pancreatic enzymes in which the underlying etiology was discovered to be heterotopic pancreas.

Oncogenic viruses like human papilloma virus (HPV) or Epstein Barr virus (EBV) are a major cause of human cancer. Viral oncogenesis has a direct impact on treatment decisions because virus-associated tumors can demand a lower intensity of chemotherapy and radiation or can be more susceptible to immune check-point inhibition. However, molecular tests for HPV and EBV are not ubiquitously available.We hypothesized that the histopathological features of virus-driven and non-virus driven cancers are sufficiently different to be detectable by artificial intelligence (AI) through deep learning-based analysis of images from routine hematoxylin and eosin (HE) stained slides. We show that deep transfer learning can predict presence of HPV in head and neck cancer with a patient-level 3-fold cross validated area-under-the-curve (AUC) of 0.89 [0.82; 0.94]. The same workflow was used for Epstein-Barr virus (EBV) driven gastric cancer achieving a cross-validated AUC of 0.80 [0.70; 0.92] and a similar performance in external validation sets. Reverse-engineering our deep neural networks, we show that the key morphological features can be made understandable to humans.This workflow could enable a fast and low-cost method to identify virus-induced cancer in clinical trials or clinical routine. At the same time, our approach for feature visualization allows pathologists to look into the black box of deep learning, enabling them to check the plausibility of computer-based image classification.

Ancillary studies facilitate accurate diagnosis of morphologically challenging mesothelial proliferations. The current diagnostic algorithm proceeds from BAP1 immunohistochemistry to CDKN2A fluorescence in situ hybridization. While MTAP immunohistochemistry has recently shown promise as a surrogate for CDKN2A fluorescence in situ hybridization, it has been examined in only a few single-institution studies. Furthermore, there are no published reports on interobserver agreement or interlaboratory reproducibility for MTAP immunohistochemistry. We performed MTAP immunohistochemistry on 20 benign mesothelial lesions and 99 malignant mesotheliomas from five mesothelioma centers in four countries, and each MTAP stain was independently interpreted by four pathologists. CDKN2A fluorescence in situ hybridization data were available for a subset of cases, and a subset of cases was subjected in MTAP immunohistochemistry in multiple laboratories to assess interlaboratory reproducibility. Interobserver agreement in MTAP immunostain interpretation was excellent for all mesothelial lesions (kappa: 0.85) and for malignant mesothelioma cases only (kappa: 0.82). Interlaboratory reproducibility was also excellent (kappa values for paired protocols: 0.77-0.89). MTAP loss by immunohistochemistry was 78% sensitive and 96% specific for CDKN2A homozygous deletion. MTAP immunohistochemistry is a reliable surrogate for CDKN2A fluorescence in situ hybridization in diagnosis of malignant mesothelioma. Interobserver agreement is excellent for interpretation of MTAP staining, and protocols performed in different laboratories yield concordant MTAP staining results. Rare cases with immunohistochemical MTAP loss may retain normal CDKN2A copy number, and the MTAP staining results should be correlated with clinicopathologic findings and other ancillary studies.

Abdominopelvic washings (APW) performed during gynecologic surgeries have become a common specimen evaluated by cytopathologists. Their role in staging of female genital tract tumors has changed significantly since they were first described, and continue to evolve. The ability of these washings to detect microscopic disease, even in the absence of gross disease, warrants the critical role that these washings play in the staging of certain female gynecologic tract tumors, allowing for optimal staging and subsequent treatment of the patient. Irrespective of the underlying pathology, the gamut of cytomorphologic findings that may be observed in APW is extensive, and ranges from benign lesions that may act as mimickers of malignancy, to both common and rare malignancies. This review discusses the changing role of APW in the staging of gynecologic tumors, and highlights the salient cytomorphologic features of these lesions, with emphasis in their correct identification, including cautionary notes to avoid over or misinterpretation. Diagn. Cytopathol. 2016. © 2016 Wiley Periodicals, Inc.

N-methyl-D-aspartate receptor encephalitis (NMDARe) is one of 13 autoimmune-mediated encephalitides that have been discovered over the last decade. This case report describes the course of a 26-year-old female who presented with new-onset seizures and insomnia, complicated by encephalitis. The initial workup ruled out common causes of encephalitis, while a transvaginal ultrasound (TVUS), and computed tomography (CT) scans of the chest, abdomen, and pelvis did not identify a mass. Based on the suspicion that she may have autoimmune encephalitis, the patient was treated with intravenous immunoglobulins and plasma exchange, but continued to deteriorate. Whole-body positron emission tomography (PET) scan identified a small hypermetabolic pelvic mass. Shortly thereafter serum and cerebral spinal fluid NMDAR antibody titers were reported as positive, prompting repetition of the TVUS, which confirmed the presence of an ovarian teratoma. The patient had a laparoscopic oophorectomy with subsequent resolution of her symptoms, further confirming the diagnosis. Despite the sensitivities of TVUS and CT of up to 94% and 98%, respectively, the teratoma was unusually small, necessitating the addition of a PET scan to identify the lesion. These neoplasms are thought to have low uptake on PET; however, it is possible that focal inflammation may have enhanced the detection. It is unlikely that the teratoma grew during hospitalization as the average growth rate is 1.8 mm per year. Regardless, the lesson that can be learned is that imaging modalities beyond CT and TVUS, such as PET, can be helpful, as identification of a resectable tumor may alter management and ultimately improve outcomes.

Hairy polyps of the nasopharynx display characteristic radiological imaging findings, including the presence of fat in the polypoid mass. Furthermore, diagnostic imaging is useful for delineating the site of origin of these lesions, which can facilitate surgical planning. For instance hairy polyps that arise from the right Eustachian tube can be amputated via a trans-nasal approach with endoscopy, but may necessitate a two stage approach in order to avoid injury to critical structures, such as the internal carotid artery. On histology, hairy polyps comprise an outer keratinizing squamous epithelium with adnexal tissue, including hair follicles, and central fibroadipose and cartilaginous tissue. These features are exemplified in this sine qua non radiology-pathology correlation article.

European Annals of Otorhinolaryngology, Head and Neck Diseases - Vol. 132 - N° 4 - p. 237-238

Annales Francaises d'Oto-Rhino-Laryngologie et de pathologie cervico-faciale - Vol. 132 - N° 4 - p. 221-222