Intracranial cholesteatoma mimicking an intracranial teratoma: a case report

Abstract

Cholesteatomas are well-defined, benign cystic lesions that arise from keratinized squamous epithelium in the temporal bone, predominantly in the middle ear. Rarely, cholesteatomas arise as primary intracranial masses, with protean symptoms and non-specific findings, creating diagnostic dilemmas. A female in her late 30s presented to the emergency department with acute severe headache and vomiting, without any focal neurological deficits or history of otologic disease. Initial neuroimaging revealed a heterogenous lesion in the left temporal bone, with imaging findings most consistent with those of a teratoma/ ruptured dermoid cyst, despite the atypical location. After awake craniotomy and resection, histopathology showed features consistent with cholesteatoma. Post-operative neuroimaging showed residual extra-axial disease at the site of surgery. Given their rarity and atypical presentation, intracranial cholesteatomas are often misdiagnosed, and a high index of suspicion is required, even in cases without an established history of otologic disease, to ensure accurate diagnosis on imaging.