Sarcomatoid carcinoma (SC) is a well defined tumor type that may occur in all organs and anatomic sites but most commonly in the head1, neck1, respiratory tract2-4, breast5, and genitourinary tract6-11. It is a biphasic tumor showing both epithelial- and mesenchymal-like differentiation; however, its carcinomatous nature is widely recognized12. SC is rare in the gastrointestinal tract. In the esophagus it accounts for less than 5% of all malignancies12-16 and approximately only 35 cases have been described in the stomach12,17-18. Very few cases have been observed in the small intestine19-20, anorectal junction21, liver22, and pancreas23-24. To our knowledge only eight cases of SC have been reported in the colon25-32. 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.