A Case of Ascending Colon Carcinoma with Rhabdoid Features

Abstract

A 78-year-old man presented with a chief complaint of upper abdominal pain. Computed tomography showed the possibility of ascending colon diverticulitis, but conservative treatment did not improve the condition. He was referred to our hospital for further examination and treatment. Colonoscopy showed a circumferential type 2 tumor in the ileocecal region, through which the scope could not pass. It was diagnosed as poorly differentiated adenocarcinoma by biopsy. Computed tomography confirmed a slightly swollen lymph node near the colon, but there was no distant metastasis. A right hemicolectomy with D3 dissection was performed. On histopathological examination, a poorly differentiated adenocarcinoma with a small amount of moderately differentiated tubular adenocarcinoma at the periphery was seen, and tumor cells had rhabdoid features, showing prominent nucleoli, eccentric nuclei, and eosinophilic cytoplasm. Immunohistochemically, the tumor cells were positive for vimentin, partially positive for CK7, and negative for CK20. Therefore, a poorly differentiated adenocarcinoma of the ascending colon with rhabdoid features was diagnosed. The patient did not receive any postoperative adjuvant chemotherapy and has been alive without recurrence for 1 year and 6 months. Colorectal cancer with rhabdoid features is very rare, and such a case was described.