Mature cystic teratoma (dermoid cyst) in the sylvian fissure: a case report and review of the literature.

Mature cystic teratoma (dermoid cyst) inside the Sylvian fissure is rare. A 14-year-old boy presented with 2 episodes of generalized tonic-clonic seizures. Using a fat-suppressed, T1-weighted sequence, magnetic resonance imaging revealed a hypointense nonenhancing mass in the left Sylvian fissure. He underwent left pterional craniotomy for total tumor resection. The pathological diagnosis was mature cystic teratoma (dermoid cyst). Headache and seizures are the leading symptoms. Cyst rupture causes inflammation of cholesterol crystals, and the cyst contents may cause seizure. Surgical resection is the treatment of choice, but radical resection is not advised if critical neurovascular structure can be injured.