Related Experiment Video
Updated: Aug 20, 2026

Murine Appendectomy Model of Chronic Colitis Associated Colorectal Cancer by Precise Localization of Caecal Patch
Published on: August 24, 2019
An appendix carcinoid tumor in a patient with hereditary nonpolyposis colorectal cancer
Catherine Miquel1, Jean-Christophe Sabourin, Dominique Elias
1Department of Pathology, Saint-Anne Hospital, Paris, France.
Abstract:
Gastrointestinal carcinoid tumors are often associated with other tumors, particularly colon adenocarcinomas; but the association between carcinoid tumors and hereditary nonpolyposis colorectal cancer (HNPCC) syndrome has not yet been explored. We report an unusual case of a 28-year-old woman with HNPCC who underwent surgery for a transverse colon adenocarcinoma in whom an appendix carcinoid tumor was incidentally found. To assess whether the carcinoid tumor displayed the characteristic molecular features of HNPCC tumors, we investigated the expression of mismatch-repair (MMR) proteins and microsatellite instability (MSI) status in both tumors. Both tumors demonstrated normal expression of the MMR proteins hMLH1, hMSH2, hMSH6, and hPMS2. Interestingly, the adenocarcinoma exhibited an MSI phenotype but the carcinoid tumor did not, indicating that these 2 tumors arose through different molecular pathways.
Related Concept Videos
Appendicitis
Appendicitis-I: Introduction
Etiology: Appendicitis can arise from various causes, primarily rooted in the obstruction of the appendix lumen. Factors contributing to this obstruction include fecal accumulation, lymphoid hyperplasia and, in...
Appendicitis-II: Diagnostic Studies and Management
Diagnosing Appendicitis
It requires a multifaceted approach, starting with a detailed physical examination to pinpoint the location and nature of the pain and identify any associated symptoms. Laboratory tests play a crucial role. A complete Blood Count (CBC) typically reveals leukocytosis (an increased number of...
Inflammatory Bowel Disease III: Crohn's Disease
Cancers Originate from Somatic Mutations in a Single Cell

