Intracranial dermoid cysts are benign lesions of embryologic origin that represent less than 0,6 % of all primary intracranial tumors ^1,2. Dermoid cysts contain ectodermal derivatives – hair follicles, sweat glands, and sebaceous glands ^1,3.
Very rarely, the lesions may rupture and disseminate their intracystic contents into the subarachnoid space and ventricles ³.
Intracranial dermoid cyst can have mixed densities on CT scan with the fatty portion and fat droplets hypodense, and areas of calcification hyperdense ². These lesions usually show a hyperintense on T1-weighted images ³, with minimal to no enhancement after gadolinium administration, but it sometimes can appear more heterogeneous because of the presence of calcifications, hair, epithelial debris, and sebaceous secretion ².

The presence of disseminated lipid droplets in the subarachnoid cisterns or ventricles on CT or MRI is diagnostic for a ruptured dermoid cyst ².

Case courtesy

• Erick Cavalcante, MD - PGY-3, Radiology Resident, Department of Radiology
• Antonio Rodrigues de Aguiar Neto, MD - Radiologist, Department of Radiology
• Hospital da Restauração – Recife, PE – Brazil