A Rare Duodenal Carcinosarcoma: A Case Report and Literature Review.

Carcinosarcoma is a biphasic malignant tumor comprising both carcinomatous and sarcomatous components; its occurrence in the duodenum is very rare. We herein report the case of a 96-year-old woman with duodenal carcinosarcoma showing rapid growth within the past year. The tumor was found to be bulging into the lumen and predominantly comprised sarcomatoid components with focal positive staining for cytokeratin. Therefore, the tumor was diagnosed as duodenal carcinosarcoma. The clinical information of the present case and our literature review of the 12 cases reported to date will help physicians diagnose and treat this rare tumor.