Jejunal tubulovillous adenocarcinoma in adenoma presenting with entero-enteric intussusception

A 73-year-old male was admitted to our institution with complaints of nausea, vomiting, and abdominal distension. Plain abdominal computed tomography (CT) suggested intussusception in the jejunum. Enhanced abdominal CT revealed the 'target-like' sign and ultrasonography revealed the 'multiple concentric ring' sign; therefore, a diagnosis of entero-enteric intussusception was made. The small intestinal obstruction and cause of the intussusception were not evident. The patient was treated conservatively with fasting and transfusion therapy to prevent intestinal obstruction. However, with no spontaneous resolution of intussusception, surgical treatment was decided. The operative findings revealed a jejunal tumor about 30 cm from the Treiz ligament, and the jejunum including the tumor with a 5 cm margin were partially resected. The resected tumor was a 35 × 50 mm soft mass spreading laterally with nodules. The pathological examinations revealed tubulovillous adenocarcinoma in the adenoma. Intussusception is rare in adults compared to children. About 45 % of cases of intussusception in adults are due to small intestinal tumors such as malignant lymphoma or lipoma, but a tubulovillous adenocarcinoma with adenoma is a rare cause of intussusception. We present a rare case of jejunal tubulovillous adenocarcinoma in adenoma presenting with entero-enteric intussusception.