Primary Intracranial Squamous Cell Carcinoma Arising in Dermoid Cyst.

Primary intracranial squamous cell carcinoma represents a rare entity. However, few cases have been reported in the literature so far. We report the case of a 32-year-old male who presented with a history of severe headache and vertigo for 3 weeks. Magnetic resonance imaging brain with contrast was done that showed a lesion measuring 5 cm × 4.8 cm in the left cerebellum near the midline which was hyperintense on T2 and hypointense on T1. It also showed ring-like heterogeneous contrast enhancement causing midline shift as well as pressure over the brainstem causing severe obstructive hydrocephalus. After emergency ventriculoperitoneal shunt placement, the patient subsequently underwent left paramedian suboccipital craniotomy and excision of space-occupying lesion. Intraoperatively, a well-demarcated capsule was identified. The entire lesion consisting of areas of calcification and hair particles was removed except the part of capsule which was adherent to the brainstem. Histopathology of the lesion showed infiltrating malignant neoplasm exhibiting papillary architecture with thick fibrovascular cores lined by stratified squamous cells. In order to rule out the possibility of metastases, systemic workup was done which yielded negative results.