Gastrointestinal: Massive gastric juvenile polyposis.

Abstract

A 46-year-old man presented with a 3-month history of fatigue and bilateral lower limb edema. His father developed colon cancer at age 30s, and his uncle has a suspected polyp discovery. Laboratory tests revealed iron deficiency anemia, hypoproteinemia, and a positive fecal immunochemical testing for occult blood. Contrast-enhanced computed tomography showed space-occupying lesions in the fundus, lesser curvature, and antrum of the stomach. Esophagogastroduodenoscopy showed massive, papillary polyposis of gastric fundus and body (Fig. 1a). Involvement was limited to the antrum, and one duodenal polypoid lesion was found. Larger polyps ranged from 30 to 40 mm in diameter (Fig. 1b), with spontaneous bleeding of some lesions. Narrow band imaging and indigo carmine dye did not reveal neoplastic micro vessels and microstructures. A few colorectal polyps were easily removed by colonoscopy, which showed features of inflammatory polyps. Enteroscopy demonstrated no bleeding in the small intestine. Piecemeal endoscopic mucosal resection was performed to deal with huge subcardial polyps with severe spontaneous bleeding. Tissue pathology confirmed a diagnosis of hamartomatous polyps without presence of dysplasia (Fig. 1c). Meanwhile, considering the family history of gastrointestinal malignancy, the patient was recommended for possible genetic testing and a heterozygous mutation in SMAD4 gene was identified. The patient exhibited a frameshift mutation in exon 11 (c.1430del:p.G477fs), leading to a premature stop codon. Finally, a diagnosis of juvenile polyposis syndrome (JPS) was proven by pathological and genetic results. Because conservative treatments and endoscopic surveillance failed to correct chronic blood loss and hypoalbuminemia, the patient finally underwent a laparoscopic total gastrectomy (Fig. 1d). The hemoglobin increased from 37 to 107 g/L, and the plasma albumin level increased from 22 to 34 g/L postoperatively. JPS is an autosomal dominant disorder with multiple juvenile polyps in the gastrointestinal tract. Gastric juvenile polyposis is rare and is most commonly associated with germline SMAD4 mutations. Unusual patterns of polyps which could mimic hyperplastic polyps make diagnosis more difficult. Typical pathological findings include the dense stroma and dilated cystic spaces. JPS should be differentiated from other diseases such as Peutz-Jeghers polyposis, Cronkhite-Canada syndrome, Ménétrier disease. Partial or total gastrectomy should be considered when high grade dysplasia occurs or when endoscopic resection may not be possible.