Spindle Cell Carcinoma (Sarcomatoid) of Colon Presenting as Weight Loss.

Sarcomatoid carcinoma of the colon is an extremely rare tumor. To date, less than 50 cases have been reported in the literature. It is rapidly growing, with a high recurrence rate, and has a very poor prognosis. Herein we present a 34-year-old male with a two-month history of weight loss, abdominal distention, and chronic history of constipation. Endoscopy was done and revealed undifferentiated adenocarcinoma of the transverse colon. On histopathology, the tumor was composed of sarcomatous and carcinomatous components. On immunohistochemistry, strong immunoreactivity for cytokeratin was found and the spindle cell component was largely vimentin positive.