Hereditary gastrointestinal carcinomas and their precursors: An algorithm for genetic testing.

Recognition of hereditary forms of gastrointestinal cancer is of great importance for patients and their families and pathologists play a crucial role in this. This review recapitulates the clinical, pathological and molecular aspects of Hereditary Diffuse Gastric Cancer and Gastric Adenocarcinoma and Proximal Polyposis of the Stomach, as well as hereditary colorectal cancer syndromes such as Lynch syndrome and gastrointestinal polyposis syndromes (including Familial Adenomatous Polyposis, Peutz-Jeghers syndrome and Juvenile Polyposis syndrome). Histopathological clues to recognize hereditary forms of gastrointestinal cancer and possible ancillary studies that can support an underlying syndrome and guide genetic testing are discussed.