Intradiploic ciliated epithelial inclusion cyst of the skull.

A 56-year-old woman presented with a cystic skull lesion in the right temporal bone detected after resection of breast cancer. She underwent resection of the skull tumor for pathological diagnosis and treatment. The tumor was covered with ciliated epithelium and there were no malignant findings. The pathological diagnosis was ciliated epithelial inclusion cyst. Intradiploic inclusion cysts of the skull presenting as a calvarial defect include epidermoid cysts and dermoid cysts, which are clinically difficult to differentiate. Ciliated epithelium lining an intradiploic inclusion cyst is very rare. Surgical resection is essential for a definitive diagnosis and differentiation from a neoplasm.