Invasive micropapillary carcinoma of the ascending colon--a report of a case.

Micropapillary carcinoma (MC) has been recently recognized to be a rare but distinctive variant of adenocarcinoma. At present, only a limited number of colorectal MC cases have been reported. We present a case of MC of the ascending colon with distant metastasis. A 61-year-old female patient was hospitalized with a complaint of abdominal pain. A diagnostic work-up revealed cancer of the ascending colon with multiple lung metastases. The patient underwent a right hemicolectomy with lymph node dissection. A peritoneal nodule was observed in the abdominal cavity during surgery, and this nodule was also resected. The pathologic findings of the colon tumor revealed components of conventional tubular adenocarcinoma and micropapillary carcinoma. Lymph nodes and a peritoneal nodule revealed tubular adenocarcinoma. MC is a rare disease but has high malignant potential. In the present case the tumor was small in size, but the patient had a peritoneal and multiple lung metastases.