A case of undifferentiated carcinoma of rectum in which patient died shortly after primary operation

A rare case of undifferentiated carcinoma of the rectum in which the patient died shortly after resection of the primary lesion is reported. A review of undifferentiated carcinoma of the large intestine in Japanese literature is analyzed. The bloody stool of a 59 year-old male was diagnosed as rectal carcinoma without distant metastasis. Low anterior resection was performed. Type 2 tumor, 5.0 x 4.7 cm in size, was found in the resected rectum. Immunohistological studies concluded the diagnosis of undifferentiated carcinoma. The tumor invaded beyond the serosa (se), and lymph node metastasis was at the root of the inferior mesenteric artery (n₃). The patient was doing well without any symptoms until discharged from the hospital. The patient was readmitted because of general fatigue, and died because of paraaortic lymph node metastasis 75 days after surgery. Undifferentiated carcinoma of the large interstine is a rare condition in Japaneses liteature. Only six cases have been reported so far. Most of the undifferentiated carcinoma had lymphatic and hematogenous metastasis, and the prognosis of these patients was extremely poor. It could be concluded that further efforts to improve prognosis of undifferentiated carcinoma of the large intestine should be focussed on adjuvant therapy instead of operation.