Adenosquamous Carcinoma of Duodenal Bulb Mimicking Subepithelial Tumor on Computed Tomography: A Case Report

Adenosquamous carcinomas of the duodenum are extremely rare neoplasms in which both glandular and squamous elements demonstrate malignant characteristics. Few cases of adenosquamous carcinoma involving the second or third segment of the duodenum have been reported in the literature. Herein, we report the first case of adenosquamous carcinoma of the bulb of the duodenum that mimicked subepithelial tumor on computed tomography in a 59-year-old man.