Small bowel obstruction caused by primary adenocarcinoma arising from an ileal tubular type foregut duplication cyst

Small bowel obstruction is a surgical emergency commonly caused by adhesions, hernia, intussusception and volvulus. Less often, it can be caused by neoplasms. Small intestine adenocarcinoma is an uncommon malignancy, while its occurrence from foregut duplication cyst is extremely rare. Herein we reported a case of complete small bowel obstruction caused by ileal adenocarcinoma arising from a tubular-type foregut duplication cyst. A 49-year-old man with history of inguinal hernia presented with vomiting, abdominal pain and distention, and constipation for 3 days. Abdominal computed tomography (CT) scan showed high-grade distal small bowel obstruction with a transition point in the terminal ileum near the ileocecal valve. Emergency exploratory laparotomy revealed a 4 × 5 cm circumferential mass at the terminal ileum. Right hemicolectomy was performed. Gross examination demonstrated a 2.5 cm long circumferential ileal stricture. Histologically, the stricture contained moderately to poorly differentiated invasive adenocarcinoma arising from ectopic foregut duplication cysts lined by mixed cuboidal and ciliated respiratory epithelial cells with focal low- and high-grade dysplasia. Peritoneal implants developed four months post surgery despite post-operative chemotherapy. Foregut duplication cyst and its derivative neoplasm should be taken into consideration in encountering adult patients with small bowel obstruction.