An unusual colon mass

A 55-year-old man came to our hospital for a colonoscopy due to periumbilical paroxysmal pain. The colonoscopy showed a huge mass near the ascending colon, with necrosis on the surface and unclear basal boundary. The structure of the residual and basal mucosa of the mass was similar to the normal intestinal mucosa. The biopsy pathology showed inflammatory cells infiltration. The patient underwent an appendectomy 30 years ago. In order to further clarify the nature of this mass, an abdominal enhanced computerized tomography (CT) was arranged for him. The CT showed segmental thickening of the ascending colon and "concentric circles" in the ileocecal part, which were consistent with intussusception like change. Then, we arranged a surgery for him. The intraoperative exploration revealed that the mass was located in the ileocecal part, about 5cm*4cm*3cm in size, soft in texture, and the intestinal tube was mildly edema. After opening the specimen, we found that the appendiceal stump had intratussed into the cecum and forming the granulomatous new tissue. Postoperative pathology showed proliferation of submucosal adipose tissue and granulation tissue, and infiltration of inflammatory cells with necrosis.