Undifferentiated Carcinoma of the Ascending Colon with Prominent Rhabdoid Features: A Case Report

ABSTRACTColorectal adenocarcinoma with rhabdoid features is extremely rare and only three cases have been previously reported. We report a 62‐year‐old man who presented with general weakness and poor oral intake for 6 months, and showed multiple masses at the duodenum, jejunum, ileum and the ascending colon. The patient underwent right hemicolectomy with small bowel segmental resection. Microscopically, the tumor masses were characterized by incohesive sheet of neoplastic cells with vesicular nuclei, large nucleoli, and abundant eosinophilic cytoplasm. Immunohistochemical studies showed strong reactivity of the tumor cells for pan‐cytokeratin, anti‐endomysial antibodies (EMA) and vimentin. This was a case of undifferentiated carcinoma with prominent rhabdoid feautures arising in the ascending colon with multiple gastrointestinal metastases.