Giant Epidermoid Cyst: A Rare Cause of Temporal Lobe Epilepsy

Introduction  Epidermoid tumors represent approximately 0.3 to 1.8% of all intracranial brain tumors. Only 1.5% of all intracranial epidermoid cysts (ECs) invade the brain and secondary epilepsy is extremely rare. Since August 2014, a 59-year-old male smoker had been presenting bad smell feelings, totaling four episodes with sudden onset and duration of 2 minutes. On September 2014, after a sense of smell episode, it evolved into loss of contact and automatic movements followed by generalized tonic-clonic movements. The brain magnetic resonance imaging revealed an extensive subtemporal lesion affecting anterior, middle, and posterior fossa with invasion of the choroidal fissure and projection to the temporal horn of the lateral ventricle. Pretemporal craniotomy with combined approaches, transsylvian and subtemporal, allowed for the excision of a white keratinized and softened lesion suggestive of EC. Discussion  The optimal surgical strategy in individuals with ECs and seizures is not established. The evaluation of the cause and risk-benefit must be held to choose the appropriate surgical strategy: lesionectomy, lobectomy, or amygdalohippocampectomy. In this case, a lesionectomy was performed due to an absence of evidence of involvement of hippocampus and amygdala. Conclusion  Epilepsy secondary to ECs is a rare association. Lesionectomy can be an option with good results without increasing the morbidity.