Objective:

 We present a case report on the rare clinical entity of the ruptured intracranial dermoid cyst and the importance of imaging in confirming the diagnosis.

Background:

Intracranial epidermoid and dermoid cysts represent about 1% of intracranial tumors. They can contain lipid, cholesterol crystals, and other ectodermal derivatives. These cysts are considered to be benign tumors, however if they rupture they can cause a significant inflammatory reaction resulting in chemical meningitis with expected symptoms of headache, nuchal rigidity, seizure, hydrocephalus, or even death. We present a case of a ruptured dermoid cyst after a mechanical fall with head trauma in an elderly male with Parkinson’s disease. CT scan was non specific and showed scattered hypoattenuation within the left lateral ventricle with Hounsfield units possibly representing lipid content. MRI was obtained to better characterize interventricular material seen on CT and showed T1 hyperintensity compatible with fat signal within the ventricles and cerebrospinal fluid. This imaging allowed for definitive diagnosis of ruptured dermoid cyst. With this information, the clinical team monitored the patient closely for signs of chemical meningitis in the case that further intervention were needed. Fortunately, the patient did well and was discharged after three days of observation. 

Design/Methods:

Not applicable

Results:

Not applicable

Conclusions:

MRI proves to be essential in confirming a diagnosis of ruptured dermoid cyst which can present nonspecifically on CT scan. Once the diagnosis is confirmed, patients must be monitored for chemical meningitis and subsequent sequelae.