Usual and Unusual Locations of Intra-Cranial Epidermoid Inclusion Cyst

Background: Epidermoid cyst is an uncommon intracranial lesion. The most common location is the cerebello-pontine angle (CPA). Unusual locations include intra-ventricular, sellar and supra-sellar regions as well as extra-axial in the temporal region. Patients and Methods: Ten patients were retrospectively included in this study. All patients were diagnosed and treated in Zagazig University hospitals and were suspected to have intra-cranial SOL on clinical basis. They were investigated by computed Tomography (CT) and conventional magnetic resonance imaging (MRI). The radiological diagnosis was correlated with histopathological diagnosis after surgical resection. Results: The overall results based on CT and MRI findings in detecting usual and unusual locations of epidermoid cysts correlated with histopathological data after surgical resection of these lesions. The CPA was the most common site for epidermoid cyst (5/10 cases), followed by 4 th ventricular epidermoid and temporal extra-axial epidermoid with or without suprasellar extension. Other unusual location was intra-dural pre-pontine site in one case at the cranio-cervical junction. Conclusion: Epidermoid cysts are benign extra-axial tumors that are accurately diagnosed by CT and MRI in CP angles but unusual locations should be considered for extraaxial masses fulfilling CT and MR characteristics of epidermoid cyst.