Cholecystic adenosquamous carcinoma mimicking Mirizzi syndrome.

From the Departments of *Surgery II, †Pathology and Laboratory Medicine and §Internal Medicine II, National Defense Medical College, Tokorozawa, Saitama, and the ‡Department of Surgery, International University of Health and Welfare Mita Hospital, Minato-ku, Tokyo, Japan M irizzi syndrome is a rare form of benign obstructive jaundice that is caused by a stone impacted either in the gallbladder neck or in the cystic duct, impinging on the right side of the common hepatic duct. This entity is often difficult to distinguish from cancers. Indeed, 6%–28% of patients with a preoperative diagnosis of Mirizzi syndrome turn out to have a cancerous stenosis. Here, we present the case of a patient with a cholecystic adenosquamous carcinoma (ASC) mimicking Mirizzi syndrome, and we emphasize some potential pitfalls in imaging study.