An unusual lesion of cerebellopontine angle as a pathological and diagnostic enigma: a comprehensive case report.

Cerebellopontine angle (CPA) tumours comprise a pathologically varied group of tumours owing to the origin of the tumour and effect on neurovascular structures, leading to a myriad of clinical manifestations. These tumours are benign, sluggish, with a low potency for malignant transformation. Malignant peripheral nerve sheath tumours (MPNST) are a malignant neoplasm of the peripheral nerves. It may develop from a pre-existing neurofibroma or may arise sporadically. Malignant peripheral nerve sheath tumours have a poor overall prognosis owing to their aggressive nature and limited therapeutic options. It comprises of 5-10% of all soft tissue sarcomas. Malignant peripheral nerve sheath tumours primarily occur in the trunk and lower extremities as opposed to intracranial location, which makes this particular site of occurrence a rarity, posing a diagnostic dilemma. We report the case of an adult male in his early 60s who presented with complaints of diplopia with headache, and a tingling sensation in the left side of his face for the past 2 months. Magnetic resonance imaging (MRI) was done, which suggested a left tentorial meningioma. Histopathological analysis revealed MPNST, which further validated the diagnosis. High mortality rates and poor prognosis stem from diagnostic dilemmas and limited treatment alternatives. This case report contributes to the existing literature by broadening the differential diagnosis of CP angle lesions and underscoring the importance of tissue diagnosis in atypical clinical presentations.