Celiac Disease: Updates on Pathology and Differential Diagnosis.

Celiac disease is a gluten-triggered immune-mediated disorder, characterized by inflammation of the enteric mucosa following lymphocytic infiltration and eventually resulting in villous blunting. There have been many developments in refining diagnostic laboratory tests for celiac disease in the last decade. Biopsy-sparing diagnostic guidelines have been proposed and validated in a few recent prospective studies. However, despite these developments, histologic evaluation of duodenal mucosa remains one of the most essential diagnostic tools as it helps in the diagnosis of celiac disease in individuals who do not fulfill the biopsy-sparing diagnostic criteria and in those not responding to a gluten-free diet. Histologic evaluation also allows for the assessment of mucosal recovery after treatment and in the identification of concurrent intestinal diseases. Therefore, pathologists should be familiar with the histologic spectrum of celiac disease and need to be aware of other disorders with similar symptoms and histopathology that may mimic celiac disease. This review aims to provide pathologists with updates on celiac laboratory testing, biopsy-sparing diagnostic criteria, histopathology, complications, and differential diagnoses of celiac disease.

Signet-Ring Cell Carcinoma Presenting as Hematochezia in a Patient with Crohn's Disease.

Signet-ring cell carcinoma is a rare adenocarcinoma, predominantly affecting the stomach and ovaries. Primary sites elsewhere are rarer. It is recognized that there is an increased cancer risk with the diagnosis of Crohn's disease. We report a patient with Crohn's disease who was diagnosed with signet-ring cell carcinoma in the setting of a Crohn's flare. Diagnosis was made with endoscopy. Treatment included laparoscopic-assisted right hemicolectomy with ileostomy with subsequent chemotherapy as an outpatient.

A case of a primary lung cancer comprised of adenocarcinoma and atypical carcinoid tumor with both components harboring BRAF p.V600E mutation.

Mixed morphology lung tumors are rare; this is the second report of a combined NSCLC and atypical carcinoid tumor. Next generation sequencing was performed on both histologically distinct patterns which identified that both components harbored a BRAF p.V600E mutation. Molecular studies inform our knowledge of the biology and aid in treatment decisions for mixed morphology lung cancers.

Indeterminate diagnoses in EUS-guided FNA of the pancreas: analysis of cytologist and clinician perceptions, cytologic features, and clinical outcomes.

INTRODUCTION: Indeterminate "atypical" or "suspicious for malignancy" diagnoses in the evaluation of pancreatic fine-needle aspiration (FNA) specimens can present challenges in the clinical management of patients with pancreatic masses. A main goal of this study was to identify, via survey, potential differences in perception between cytologists and clinicians with regard to the implications of, and factors contributing to, indeterminate diagnoses. We also evaluated clinical practice at our institution as it relates to such diagnoses and identified clinicopathologic features associated with indeterminate diagnoses, which allowed for correlation with survey results. MATERIALS AND METHODS: Online surveys were sent to cytologists and clinicians to gather information on the respondents' experiences with pancreatic endoscopic ultrasound-guided FNA and their perceptions about the indeterminate diagnostic categories. Cytological specimens and patient medical records were reviewed to collect data on specimen acquisition, cytological features, tumor characteristics, and patient management. RESULTS: Survey responses revealed that cytologists and clinicians held similar perceptions of the clinical impact of the indeterminate categories but had dissimilar ideas on the factors contributing to these diagnoses. Statistically significant associations were identified between indeterminate diagnoses and the following variables: number of passes performed; adequacy on rapid on-site evaluation; repeat FNA procedures; lesions with cystic changes; and well-differentiated tumor cytomorphology. CONCLUSIONS: Awareness of the perceptions of cytologists and clinicians about, as well as the clinical features and cytologic variables associated with, "indeterminate" cases has the potential to improve patient care.

Deep Learning for Classification of Colorectal Polyps on Whole-slide Images.

CONTEXT: Histopathological characterization of colorectal polyps is critical for determining the risk of colorectal cancer and future rates of surveillance for patients. However, this characterization is a challenging task and suffers from significant inter- and intra-observer variability. AIMS: We built an automatic image analysis method that can accurately classify different types of colorectal polyps on whole-slide images to help pathologists with this characterization and diagnosis. SETTING AND DESIGN: Our method is based on deep-learning techniques, which rely on numerous levels of abstraction for data representation and have shown state-of-the-art results for various image analysis tasks. SUBJECTS AND METHODS: Our method covers five common types of polyps (i.e., hyperplastic, sessile serrated, traditional serrated, tubular, and tubulovillous/villous) that are included in the US Multisociety Task Force guidelines for colorectal cancer risk assessment and surveillance. We developed multiple deep-learning approaches by leveraging a dataset of 2074 crop images, which were annotated by multiple domain expert pathologists as reference standards. STATISTICAL ANALYSIS: We evaluated our method on an independent test set of 239 whole-slide images and measured standard machine-learning evaluation metrics of accuracy, precision, recall, and F1 score and their 95% confidence intervals. RESULTS: Our evaluation shows that our method with residual network architecture achieves the best performance for classification of colorectal polyps on whole-slide images (overall accuracy: 93.0%, 95% confidence interval: 89.0%-95.9%). CONCLUSIONS: Our method can reduce the cognitive burden on pathologists and improve their efficacy in histopathological characterization of colorectal polyps and in subsequent risk assessment and follow-up recommendations.

Increased alloimmunisation and transfusion reaction reporting in patients with solid-phase panreactivity.

BACKGROUND: Automated solid-phase antibody screening uses red blood cell (RBC) membranes immobilised on polystyrene test wells to detect RBC specific antibodies. Despite its time-saving and labour-saving benefits, this method produces a higher rate of nonspecific reactivity compared with manual screening. Solid-phase panreactivity (SPP) is characterised by panreactivity (ie, all test cells reacting) in solid-phase testing accompanied by a negative autocontrol and a lack of reactivity when the same screening cells are tested in tube. The mechanisms underlying SPP and its clinical significance remain unclear. The goals of this study were to describe the prevalence of SPP at our institution and determine the alloimmunisation and transfusion reaction rates within this population. METHODS: Data were collected on all patients undergoing type and screen testing over a 6-year period. Study patients undergoing subsequent transfusion were evaluated for reported transfusion reactions and development of new alloantibodies. RESULTS: Of the 76 051 patients studied, 0.7% demonstrated SPP of which 11% developed new alloantibodies. The transfusion reaction reporting rate among patients with SPP was 2%. CONCLUSIONS: Our data suggest that patients with SPP have higher rates of reported transfusion reactions and alloantibody development compared with those without SPP.

Primary Intraprostatic Synovial Sarcoma.

Primary intraprostatic synovial sarcoma is a rare presentation of an otherwise well-studied disease, and it is one of the few primary sarcomas to occur in the prostate. Ancillary diagnostic techniques including immunohistochemistry and molecular genetics are useful to establish a definitive diagnosis. Despite its unorthodox location, it shares histologic and molecular genetic characteristics with tumors found elsewhere in the body. Most notably, the chromosomal translocation t(X;18)(p11;q11) encodes a chimeric transcription-activating protein, SS18-SSX, which has been identified as the primary driver mutation. The SS18-SSX fusion gene provides a consistent and dependable means of establishing a definitive diagnosis via reverse transcription-polymerase chain reaction or fluorescence in situ hybridization. Recent studies have continued to provide insight into the oncogenesis of this disease. The goal of this review is to elaborate on the clinicopathologic characteristics and underline those techniques that best facilitate the diagnosis of primary intraprostatic synovial sarcoma.

Plasmablastic lymphoma mimicking carcinomatosis: A case report and review of the literature.

First identified as a distinct disease entity in HIV-positive patients, plasmablastic lymphoma is a rare aggressive disease which arises predominantly in men and is associated with immunodeficiency of all causes. Although its exact etiology is poorly understood, Epstein-Barr virus infection and MYC gene aberrations have been implicated in its development in both HIV-positive and HIV-negative patients. The disease typically involves extranodal sites with a predilection for the oral cavity but may occur in other locations. Here we present a case of plasmablastic lymphoma diffusely involving the omentum and peritoneal cavity of an immunocompetent woman, clinically mimicking an ovarian carcinomatosis. To the best of our knowledge, this is the first case in which plasmablastic lymphoma has presented as peritoneal lymphomatosis. Diagn. Cytopathol. 2017;45:243-246. © 2016 Wiley Periodicals, Inc.