A Case of gastric juvenile polyposis successfully diagnosed by identification of a germline SMAD4 mutation

Gastric juvenile polyposis is a rare disease without specific colorectal lesions, and accordingly, clinical diagnosis is extremely hard. Recent studies have elucidated the close association between this rare disease and germline SMAD4 mutations. Here, we report a case of gastric juvenile polyposis successfully diagnosed by identification of a germline SMAD4 mutation. A 42-year-old Japanese woman was referred to our hospital for chronic anemia and hypoalbuminemia refractory to medical treatment. Before referral to our hospital, the patient received steroids under the diagnosis of Cronkhite-Canada syndrome, which failed to improve the symptoms. Endoscopic examination revealed numerous gastric polyps covered with abundant mucus throughout the stomach. Colonoscopy revealed no specific findings in the colorectum. The patient received laparoscopy-assisted total gastrectomy. Histopathological examination of the stomach did not reach definite diagnosis. However, gene analysis successfully identified a novel germ line SMAD4 mutation (c. 904delT [p. Trp302fsX34]), which confirmed diagnosis of gastric juvenile polyposis. The present case suggests efficacy of mutation analysis for germline SMAD4 mutations when gastric juvenile polyposis is suspected.