Primary Meningeal Melanocytoma in the Left Temporal Lobe Associated with Nevus Ota: a Case Report and Review of the Literature

Abstract

Primary melanocytic neoplasms of the central nervous system are rare lesions arising from melanocytes of the leptomeninge that are found at highest density underneath the brain stem and along the upper cervical spinal cord. Thus most reported cases of meningeal melanocytomas are located in the posterior fossa and the spinal cord, and presentation of a supratentorial tumor is rare. A 19-year-old man presented with a headache and seizure at our department. Neurological examinations were otherwise normal. On physical examination he had asymptomatic, bluish, speckled, and well-demarcated hyperpigmented macules on the left midface extraorally. A left temporal space-occupying lesion was seen on magnetic resonance imaging. The mass was hyperintense on T1-weighted images and isointense on T2-weighted images. Enhancement was shown on contrast-enhanced magnetic resonance imaging (MRI). The preoperative diagnosis was meningioma. Gross complete resection was performed. Pathological studies led to the diagnosis of meningeal melanocytoma World Health Organization (WHO) grade I. The patient received oncologic consultation. Because total resection of the tumor was achieved and its histopathologic grade was benign (WHO grade I), radiotherapy was not advised for the patient and he followed up every 6 months. No tumor was seen on follow-up MRI one year after surgery. Presentation of meningeal melanocytoma in the supratentorial compartment is rare, and its combination with nevus Ota has been reported in very few cases. Although this lesion is benign, it might behave aggressively. Complete surgical resection of the lesion is the preferred therapeutic option.