Gastric adenocarcinoma arising from fundic gland polyps in a patient with familial adenomatous polyposis syndrome.

Familial adenomatous polyposis (FAP) is a rare hereditary syndrome characterized by multiple colorectal polyps and early development of colorectal cancer. Although FAP uniformly involves the large bowel, it may also produce lesions in the stomach and upper intestinal tract. Fundic gland polyps are the most common gastric lesion in FAP. In the general population, these polyps are considered benign and have no malignant potential. However, in FAP patients, fundic gland polyps have been occasionally recognized as precursor lesions from which invasive cancer may develop. Herein, we present a case of gastric adenocarcinoma arising from fundic gland polyps in an FAP patient. We also review reported cases of gastric cancer in FAP and FAP variant patients in an effort to better understand the pathology, clinical course, and optimal screening and treatment strategies for this disease manifestation.