Intradiploic epidermoid cyst with focal internal enhancement.

We report a case of intradiploic epidermoid cyst with focal internal enhancement. The patient was a 55-year-old woman presenting with right temporal head protrusion and head heaviness. Skull radiography and computed tomography demonstrated an expansile mass in the right diploic space. On magnetic resonance imaging, the mass showed makedly high signal T2-weighted images (T2WI) and intermediate to low signal on T1WI. On contrast-enhanced T1WI, there was nodular internal enhancement, which corresponded to neovascularity on pathology, as well as rim-like enhancement. It should be noted that internal enhancement, an indicator of malignant transformation, may be seen even in a benign epidermoid cyst.