A Rare Cause of Hydrocephalus: Dermoid Cyst Rupture

Dermoid cysts (DC) are originated from ectodermal cells, which stay in the intracranial region in the course of neural tube closure between 3 and 5 weeks of the embryonic period. They are benign, slowly growing, usually asymptomatic, quite rare inclusion cysts, and consist <0.5% of primary intracranial tumors. Hydrocephalus is a disease that goes with impairment in cerebrospinal fluid circulation and has a complex physiopathology. In this report, we present a DC patient who developed confusion on postoperative day 4, after spinal surgery caused by hydrocephalus following epidermoid rupture. Computed tomography of the brain revealed fat blisters caused by fat crystals in the right sylvian fissure, anterior interhemispheric fissure, and basal cisterns. There was minimal dilation in lateral ventricles. Computed tomography obtained a couple of weeks later revealed significant triventricular hydrocephalus. On cranial magnetic resonance imaging, there were hyperintense foci in T1A, T2A, and FLAIR series and significant triventricular hydrocephalus. An external ventricular drainage system was inserted because of progressive hydrocephalus developing due to rupture of epidermoid tumor. The patient whose confusion improved in the early postoperative period and the external ventricular drainage system was removed on day 5. In conclusion, DCs and their rupture have become a more commonly encountered condition with increased use of magnetic resonance imaging. Proper treatment planning may be done for this potentially fatal complication of hydrocephalus due to ruptured epidermoid cyst through radiologic imaging.