[A case of intussusception caused by low-grade appendiceal mucinous neoplasm with high serum levels of carcinoembryonic antigen resected by laparoscopy-assisted colectomy].

: The patient was a 43-year-old woman who visited our hospital with a primary complaint of intermittent abdominal pain. Upper gastrointestinal endoscopy revealed mild gastritis. The patient was treated with oral drugs, and the course was followed. Subsequently, the abdominal pain aggravated, and computed tomography (CT) was performed, in which right colic intussusception with a 4 cm cystic mass in the advanced portion was noted. Reduction by enema was attempted on the same day; however, a residual tumorous lesion was present in the ileocecal region. The patient was diagnosed with a cecal submucosal tumor with intussusception, and therefore, laparoscopic surgery was performed. Intussusception of the entire appendix in the ascending colon was noted, for which laparoscopic ileocecal resection was performed. In the excised specimen, a cystic lesion comprising the appendix filled with mucus was present. The postoperative recovery was favorable, and the patient was discharged on the seventh postoperative day. The lesion was histopathologically diagnosed as low-grade appendiceal mucinous neoplasm.