Gastrointestinal Stromal Tumours (GISTs) with KRAS Mutation: A Rare but Important Subset of GISTs.

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the GI tract, usually found in the stomach, jejunum, and ileum. Typically, they are or -mutated, allowing for targetable treatments with tyrosine kinase inhibitors such as imatinib. Here, we present two -mutated wild-type gastrointestinal tumours (GISTs).

Appendiceal Well-Differentiated Neuroendocrine Tumors: A Single-Center Experience and New Insights into the Effective Use of Immunohistochemistry.

. Appendiceal well-differentiated neuroendocrine tumor is the most common histological type of appendiceal tumor. The majority of tumors are found incidentally at the tip of the appendix, with few exceptions.

Establishment of a remote diagnostic histopathology service using whole slide imaging (digital pathology).

Background: Whole slide imaging (WSI) has diverse applications in modern pathology practice, including providing histopathology services to remote locations.

Materials And Methods: Utilising an existing contractual partnership with a Northern Ontario group of hospitals, the feasibility of using WSI for primary diagnostic services from Toronto was explored by the dedicated working group. All aspects explored from information technology (IT), laboratory information system (LIS) integration, scanning needs, laboratory workflow and pathologist needs and training, were taken into account in the developing the rationale and business case.

Review of pathology and cost benefit analysis of hernia sacs processed over a 19-year period.

Aim: Hernia sacs with pathological evaluation over a 19-year period were analysed with regards to pathological diagnoses, full costing and the impact on patient management.

Materials And Methods: The database of the Department of Pathology were searched over the study period (2001 to 2019 inclusive) for hernia sacs. The total cost of complete pathology examination was calculated on average numbers and rates of pay that existed over the study period.

Morphological classification of pancreatic ductal adenocarcinoma that predicts molecular subtypes and correlates with clinical outcome.

Introduction: Transcriptional analyses have identified several distinct molecular subtypes in pancreatic ductal adenocarcinoma (PDAC) that have prognostic and potential therapeutic significance. However, to date, an indepth, clinicomorphological correlation of these molecular subtypes has not been performed. We sought to identify specific morphological patterns to compare with known molecular subtypes, interrogate their biological significance, and furthermore reappraise the current grading system in PDAC.

Predicting Underlying Neoplasms in Appendiceal Mucoceles at CT: Focal Versus Diffuse Luminal Dilatation.

The purpose of this study was to determine whether a novel morphologic characteristic of appendiceal mucoceles at CT-focal distal appendiceal dilatation with a segment of morphologically normal appendix proximally-could predict an underlying neoplastic pathologic abnormality before surgery and histopathologic assessment. A retrospective study was performed that assessed CT cases from 2012 through 2014. Cases showing morphologic features of a mucocele were identified and categorized into two subgroups: focal distal dilatation with a segment of normal appendix proximally and generalized appendiceal dilatation.

Gastric foveolar dysplasia: a survey of reporting habits and diagnostic criteria.

This study aimed to ascertain views, incidence of reporting and diagnostic criteria for gastric foveolar dysplasia. A questionnaire, a post-questionnaire discussion and microscopic assessment of selected cases was conducted by gastrointestinal pathologists to explore the above-stated aims. Fifty-four percent of respondents never or rarely diagnosed gastric foveolar-type dysplasia.

Regression grading in neoadjuvant treated pancreatic cancer: an interobserver study.

Aim: Several regression grading systems have been proposed for neoadjuvant chemoradiation-treated pancreatic ductal adenocarcinoma (PDAC). This study aimed to examine the utility, reproducibility and level of concordance of three most frequently used grading systems.

Methods: Four gastrointestinal pathologists used the College of American Pathologists (CAP), Evans, MD Anderson Cancer Centre (MDA) regression grading systems to grade 14 selected cases (7-20 slides from each case) of neoadjuvant chemoradiation-treated PDAC.

The first report of a previously undescribed EBV-negative NK-cell lymphoma of the GI tract presenting as chronic diarrhoea with eosinophilia.

A 74-year-old man presented with a 2-month history of watery diarrhoea. His complete blood count showed lymphopaenia and marked eosinophilia. Investigations for common infectious causes including Clostridium difficile toxin, stool culture, ova and parasites were negative.

Primary cystic peritoneal masses and mimickers: spectrum of diseases with pathologic correlation.

Cystic lesions within the peritoneum have been classified classically according to their lining on histology into four categories-endothelial, epithelial, mesothelial, and others (germ cell tumors, sex cord gonadal stromal tumors, cystic mesenchymal tumors, fibrous wall tumors, and infectious cystic peritoneal lesions). In this article, we will proceed to classify cystic peritoneal lesions focusing on the degree of radiological complexity into three categories-simple cystic, mildly complex, and cystic with solid component lesions. Many intra-abdominal collections within the peritoneal cavity such as abscess, seroma, biloma, urinoma, or lymphocele may mimic primary peritoneal cystic masses and need to be differentiated.

Infection and esophageal cancer.

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on infection and cancer, and includes commentaries on the influence of bacterial infections on mucin expression and cancer risk; the role of esophageal bacterial biota in the incidence of esophageal disease; the association between human papilloma virus (HPV) and esophageal squamous cell carcinoma; the role of HPV in esophageal adenocarcinoma; the role of Helicobacter pylori in cardiac carcinoma; and the role of Epstein-Barr virus infection in esophageal cancer.

Gastric biopsies: the gap between evidence-based medicine and daily practice in the management of gastric Helicobacter pylori infection.

Background: Many consider histology to be the gold standard for Helicobacter pylori detection. Because the number and distribution of H pylori organisms vary, particularly in patients taking proton pump inhibitors (PPIs), the American Gastroenterological Association recommends discontinuing PPIs two weeks before endoscopy, and taking biopsies from both the body and antrum.

Objective: To assess the influence of clinical practice on the histopathological detection of H pylori infection.

Incidental perivascular epithelioid cell tumor in an inguinal hernia sac.

Perivascular epithelioid tumors (PEComa) are uncommon mesenchymal neoplasms demonstrating positivity for muscular and melanocytic immuno-markers. Included in this category are angiomyolipoma, lymphangioleiomyomatosis, and clear cell sugar tumors. Lesions which do not fit into these categories are classified as "not otherwise specified".

Hernia sacs: is histological examination necessary?

The hernia sac is a common surgical pathology specimen which can occasionally yield unexpected diagnoses. The College of American Pathologists recommends microscopic examination of abdominal hernias, but leaves submission of inguinal hernias for histology to the discretion of the pathologist. To validate this approach at a tertiary care centre, we retrospectively reviewed 1426 hernia sacs derived from inguinal, femoral and abdominal wall hernias.

International study group on rectal cancer regression grading: interobserver variability with commonly used regression grading systems.

The aim of this study was to ascertain the level of concordance among gastrointestinal pathologists for regression grading in rectal cancers treated with neoadjuvant chemoradiation. Seventeen gastrointestinal pathologists participated using the Mandard, Dworak, and modified rectal cancer regression grading systems to grade 10 representative slides that were selected from 10 cases of rectal cancer treated with long-course neoadjuvant chemoradiation. The slides were scanned with a whole-slide scanner generating dynamic digitized images.

Light chain deposition disease affecting the gastrointestinal tract in the setting of post-living donor kidney transplantation.

Light chain deposition disease (LCDD) is an uncommon, clonal plasma cell proliferative disorder, in which monoclonal immunoglobulin light chains deposit in various tissues, resulting in organ dysfunction. Gastrointestinal (GI) involvement has been described in both primary and secondary amyloidosis, but has rarely been reported in LCDD, and only as an incidental finding. We report a case of LCDD in living related kidney transplant recipient presenting with severe GI dysmotility, weight loss and progressive allograft dysfunction.

A multi-centre pathologist survey on pathological processing and regression grading of colorectal cancer resection specimens treated by neoadjuvant chemoradiation.

To ascertain the approach and degree of consensus of pathologists in the handling and regression grading of colorectal cancer resection specimens treated with neoadjuvant chemoradiation, a ten-part questionnaire was circulated to 18 gastrointestinal pathologists in eight countries. The questions were specific and addressed pertinent issues related to colorectal cancer with neoadjuvant chemoradiation. There is a lack of consensus on how to handle the specimen, number of sections taken, correlation with pre- and post-operative radiological imaging, and especially, regression grading schema employed.

Vasculopathic changes, a somatostatin-producing neuroendocrine carcinoma and a jejunal gastrointestinal stromal tumor in a patient with type 1 neurofibromatosis.

A 36-year-old male with neurofibromatosis type 1 (NF-1) presented with symptoms of obstructive jaundice. Imaging showed a periampullary mass, which on endoscopic retrograde cholangiopancreatography biopsy proved to be a somatostatinoma. A Whipple's procedure was performed and a somatostatinoma of the duodenum was confirmed.

Psammomatous melanotic schwannoma presenting as colonic polyps.

Psammomatous melanotic schwannoma is an uncommon neoplasm that usually occurs in the setting of Carney's complex. They can occur in the gastrointestinal tract with preferential location in the stomach. A 43-year-old female presented with two colonic polyps at routine endoscopy.