A Case of Idiopathic Appendiceal Intussusception Difficult to Distinguish from an Appendiceal Tumor

Abstract

A case in which laparoscopic ileocecal resection was performed for a suspected asymptomatic appendiceal tumor, and postoperative histopathological examination showed idiopathic appendiceal intussusception is reported. The patient was a 73-year-old man. Colonoscopy for screening showed a red mucosal protrusion in the opening of the appendix. Contrast-enhanced computed tomography (CT) showed the lesion as a mass protruding into the lumen of the cecum. The appendix was mildly swollen. An appendiceal tumor was suspected, and the patient was referred to our department. Laparoscopic ileocecal resection was performed because cecal resection may result in positive margins. On macroscopic examination, the resected specimen showed reddened mucosa protruding like a polyp from the opening of the appendix. On histopathological examination, the appendiceal mucosa was inverted due to intussusception and had a polyp-like elevation. Idiopathic appendiceal intussusception was diagnosed because no specific inflammatory or malignant findings were seen within the protrusion. Idiopathic appendiceal intussusception should be considered in the differential diagnosis of mass lesions of the appendix.