Intradural epidermoid cysts are usually extra-axial lesions, most commonly found in the cerebellopontine angle, and rarely in the middle cranial fossa. They are often called congenital cholesteatoma because of their cholesterol content. They are frequently identified during the third and fourth decade as they grow by accumulation of the desquamated material. There is no obvious gender bias. Most intradiploic epidermoid cysts are manifested clinically as small, asymptomatic lumps in the skull.
Symptoms are headache and tenderness.
Our patient had headache, with moderate to severe localized tenderness with no palpable mass. The midline lesions over the bridge of the nose, or near the torcular herophili, are of great importance because of the great frequency of extra- or intracranial extension, which may result with infection or involve the major venous sinuses or the underlying brain. The margins are sharply sclerotic. 12 CT scan provides additional information about the extent of the bony defect caused by the cyst. The differential diagnosis of intradiploic epidermoid cysts includes dermoid cyst hemangioma, eosinophilic granuloma, and in the orbitofrontal region, cholesterol granuloma.