April 2021 — Gastroenterology and Surgical Pathology Case 2
A 35-year-old woman presented with gastric bleeding and was found to have a 3.4 cm mass involving the stomach and a 1.8 cm paracaval nodule. Previously, the patient had a paraganglioma removed from the abdomen.
For which predisposition syndrome would testing be most important for prognosis?
- MMR (MLH1, PMS2, MSH2, MSH6)
The correct answer is ...
The correct answer is: SDHB.
- The gastric tumor is a gastrointestinal stromal tumor (positive for CD34 and CD117) and the abdominal tumor is a paraganglioma. These tumors can occur in a patient with succinate dehydrogenase (SDH) deficiency. In a younger person with synchronous or meta-synchronous GIST and paraganglioma, this suggests the possibility of a predisposition syndrome and can be further studied with SDHB immunohistochemistry. In this case, SDHB IHC was negative in the gastric GIST as well as the paracaval paraganglioma, indicating a possible correlation with SDHB deficiency syndrome (see figures 5 and 6).
- PTEN is associated with Cowden syndrome, which predisposes to hamartomas in the esophagus and stomach and increased incidence of colorectal adenocarcinoma.
- MMR (MSH2, MSH6, MLH1, PMS2) Mismatch repair protein deficiency is associated with Lynch syndrome and predisposition to colorectal adenocarcinoma.
- CDH1 mutations predispose to gastric signet ring cell carcinoma. (Figures 5 and 6)
- WHO Classification of Tumours Editorial Board. Digestive system tumours [Internet]. Lyon (France): International Agency for Research on Cancer; 2019 [cited 2021 Mar 4]. (WHO classification of tumours series, 5th ed.; vol. 1). Available from: https://tumourclassification.iarc.who.int/.
David Nolte, M.D.
Fellow, Surgical Pathology
Rondell Graham, M.B.B.S.
Consultant, Anatomic Pathology
Associate Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine and Science