Primary melanocytic tumor of the cerebellopontine angle mimicking acoustic schwannoma: Case report

Intra-cranial melanomas are commonly metastatic, from primary melanoma elsewhere in the body. The primary occurrence of a melanoma in the brain parenchyma is rare. We report a case of 26-year aged woman who presented with headache, hearing loss, mild cerebellar signs. On imaging, a space occupying lesion was found in the right cerebellopontine angle and a preoperative diagnosis of schwannoma/ meningioma was made. She underwent right retro-mastoid sub-occipital craniectomy and excision of a blackish vascular tumour. Histopathological examination revealed a melanocytoma intermediate grade, mib Index 4-5%. Search for dermal, mucous and ocular lesions were negative. She received image guidance adjuvant radiation to the post- operative tumour bed to 50.4 Gy/28 fractions @ 180 cGy tumor. She tolerated the treatment well and is symptom free 12 months after treatment. We report a rare case of primary melanocytic tumour of the cerebellopontine angle.