Sarcomatoid carcinoma of the colon: a case report with literature review.

Sarcomatoid carcinoma (SC) is a well defined tumor type that may occur in all organs and anatomic sites but most commonly in the head, neck, respiratory tract, breast, and genitourinary tract. It is a biphasic tumor showing both epithelial- and mesenchymal-like differentiation; however, its carcinomatous nature is widely recognized. SC is rare in the gastrointestinal tract. In the esophagus it accounts for less than 5% of all malignancies and approximately only 35 cases have been described in the stomach. Very few cases have been observed in the small intestine, anorectal junction, liver, and pancreas. To our knowledge only eight cases of SC have been reported in the colon. We report a case of primary colonic SC. Both morphological and immunohistochemical analyses are provided along with an evaluation of the unusual clinical history, therapeutic implications, and controversial differential diagnosis.