Smad4 germline pathogenic variant-related gastric juvenile polyposis with adenocarcinoma treated with laparoscopic total gastrectomy: A case report

Objective: Rare disease Background: Juvenile polyposis syndrome is an uncommon, autosomal-dominant hereditary disease that is distinguished by multiple polyps in the stomach or intestinal tract. It is associated with a high risk of malignancy. Pathogenic variants in SMAD4 or BMPR1A account for 40% of all cases. Case Report: A 49-year-old woman underwent esophagogastroduodenoscopy because of exacerbation of anemia. She had numerous erythematous polyps in most parts of her stomach. Based on biopsy findings, juvenile polyposis syn­drome (JPS) was suspected morphologically, but there was no evidence of malignancy. Colonoscopy showed stemmed hyperplastic polyps and an adenoma; video capsule endoscopy revealed no lesions in the small in­testine. After preoperative surveillance, laparoscopic total gastrectomy with D1 lymph node dissection was performed to prevent malignant transformation. The pathological diagnosis was juvenile polyp-like polyposis with adenocarcinoma. In addition, a germline pathogenic variant in the SMAD4 gene was detected with genet­ic testing. Conclusions: JPS can be diagnosed with endoscopy and genetic testing. Further, appropriate surgical management may pre­vent cancer-related death in patients with this condition.