Background: Dermoid tumors are benign congenital cystic lesions that usually present with local mass effect. Very rarely, they present as spontaneous ruptures. Traumatic rupture of these dermoid cysts is an extremely rare event and only a handful of such cases have been ever reported.
Case description: A 47-year-old female presented to our hospital with a ruptured intracranial dermoid cyst following a mild head injury. The ruptured cyst contents were disseminated into the subarachnoid and intraventricular compartments, resulting in an obstructive hydrocephalus. After medical stabilization, she underwent gross total resection of the cyst using combined transsylvian, transcortical-transventricular, and sub-frontal approaches. A ventriculo-peritoneal shunt was eventually also needed.
Conclusion: Traumatic rupture of an intracranial dermoid cyst is an extremely rare event and this is only the fourth such case reported in the literature. We presume that this rupture occurs due to sudden shifts in the cyst sac, which is adherent to some partially mobile intracranial contents. Although computed tomography (CT) is often adequate in making a diagnosis of this entity, magnetic resonance imaging (MRI) provides complete characterization of the extent of lipid dissemination, and is essential for operative planning. Intravenous steroids at presentation are helpful in managing the aseptic meningitis associated with rupture. Complete surgical resection is the goal, but must be weighed against the risk for injury to nearby vital structures. Hydrocephalus should be managed promptly, and patients should be monitored for it closely in the perioperative period. Even though the recurrence rate with subtotal resection is extremely rare, follow up should be done routinely.
Keywords: Aseptic meningitis; communicating hydrocephalus; dermoid cyst; intracranial rupture.