A CASE OF EXPANSIVE POLYPOID UNDIFFERENTIATED CARCINOMA OF THE SIGMOID COLON WITH INVAGINATION

Undifferentiated carcinomas of the colon are rare, especially macroscopic expansive polypoid type. Only few cases have been reported so far. Recently, we experienced such a rare case. A 71-year-old male patient came in the hospital because of some symptoms suggestive of intestinal obstruction. General diagnostic work-up, including colon biopsy, revealed a primary undifferentiated carcinoma of the sigmoid colon and radical operation was performed. Undifferentiated carcinomas of the colon and rectum would demand general diagnostic work-up in the differentiation from others such as carcinoid, malignant lymphoma, malignant melanoma, and metastasis of pulmonary carcinoma. In addition appropriate selection of antitumor drugs in terms of histological findings would be important in the adjuvant chemotherapy.