Image-diagnostic features of mature cystic teratomas of the pancreas: report on two cases difficult to diagnose preoperatively.

This report documents the findings of two rare cases of mature cystic teratoma of the pancreas. Although they could not be diagnosed preoperatively, our retrospective report suggests that the combined diagnosis of ultrasonography (US), enhanced computed tomography (CT), and magnetic resonance cholangiopancreatography (MRCP) might allow differentiation from other cystic lesions such as mucinous cystic tumors (MCTs) and intraductal papillary-mucinous tumors (IPMTs). Since the cystic teratomas were both filled with keratinous and sebaceous material, they were echogenic, appearing as solid masses on US. Enhanced CT showed their cystic nature, with values slightly higher than water, and MRCP revealed defects of internal signals.