Anterior Cranial Fossa Hemorrhagic epidermoid Cyst: CT and MRI Findings

We reported a rare case of hemorrhagic epidermoid cyst located in the anterior cranial fossa. A 66-year-old female presented with progressive nausea and vomiting for one month. Computed tomography revealed a mixed high and low density mass in the right lateral frontal basal region, with a few stippled calcifications at its inferior wall. Magnetic resonance imaging showed that the lesion was largely hyperintense on T1 weighted images and was of heterogeneously mixed high and low signal intensity on T2 weighted images. The lesion had a surrounding dark r im and exhibited curvilinear contrast enhancement in its medial margin. The patient underwent total surgical removal of the mass and did well during one year follow-up. Recognition of imaging findings facilitates appropriate preoperative differential diagnosis and is helpful to prevent leakage of cystic content during surgery. Intracranial epidermoid cyst (EC) is rare and has been reported to constitute 0.2%–1.8% of primary intracranial tumors [1]. It is a benign extraaxial lesion and in about 40-50% of cases are located in the cerebellopontine angle [1]. ECs also occur in the fourth ventricle (17%) and the sellar and/or parasellar regions (10%-15%). Less common locations include the cerebral hemispheres or brainstem. All are located off the midline. Because of its avascular nature, intracranial EC is seldom complicated with hemorrhage. Only a few such cases have been reported in the posterior cranial fossa and middle cranial fossa [2-4]. To our knowledge, this is the first reported case of hemorrhagic EC occurring in the anterior cranial fossa.