Malignant transformation of intracranial dermoid cyst into squamous cell carcinoma: an uncommon pathology with serious consequences

We present the case of a symptomatic 46-year-old female with near 30-year history of left cerebellopontine angle dermoid cyst. Subtotal resection of lesion subsequently revealed malignant transformation of cystic structure into squamous cell carcinomas (SCC) and disseminated leptomeningeal disease. She underwent adjuvant radiotherapy and immunotherapy. Her recovery was complicated by hydrocephalus requiring a cerebrospinal fluid (CSF) diversion shunts and chemical meningitis. She remains well at 7 months post-operatively.