Spinal Nerve Root Extradural Melanocytoma Progressing to Malignant Melanoma: A Case Report with Review of Literature.

Melanocytomas are rare benign pigmented tumors arising from the leptomeninges with a very remote chance of progressing to malignant melanoma. They have a predilection for occurring in the posterior fossa or in the intradural extramedullary region of the cervical spine. We report the first case of malignant transformation of a nerve root (extradural) melanocytoma wherein immunotherapy has been added for its treatment. Only four such cases of malignant transformation of central nervous system melanocytoma have been reported in the literature. Definite diagnosis in such cases is based on immunohistochemistry evaluation. Surgical resection with adjuvant radiotherapy and immunotherapy is the recommended treatment.