Movable oil in the brain: intracranial ruptured dermoid tumors

Abstract

that contain dermal elements with sebaceous glands, produce fat or oil within their capsules. When such tumors rupture, fatty or oily globules thus escape into the ventricles and/or into the subarachnoid spaces.1–5 We report two such cases. The first case is that of a 26-year-old man who developed a dull headache and diplopia. Computerized tomography (CT) and magnetic resonance (MR) imaging revealed a dermoid cyst in the middle fossa. At surgery oily globules were noted to be floating and moving freely within the subarachnoid space (Fig. 1). The second case is that of a 14-year-old boy with a 5-year history of intermittent headache. A CT scan showed a large pineal tumor (Fig. 2). A subtotal resection of the tumor was performed and histological examination revealed the tumor to be a mature teratoma with predominantly dermal elements and numerous sebaceous glands. Spontaneous rupture of intracranial dermoid tumors can cause various sequelae. Such patients may be asymptomatic or they may develop aseptic meningitis, headache, acute hemiparesis, seizure, or transient cerebral ischemia due to vasospasm.1–5 The characteristics of our two cases included the presence of mobile fatty or oily globules in the subarachnoid or intraventricular spaces and the presence of dermal elements, especially numerous sebaceous glands. When an intracranial mass lesion exhibits floating or movable oil in the brain on CT and/or MR imaging, the diagnosis of either a dermoid cyst or a teratoma containing numerous sebaceous glands is strongly indicated.