Malignant blue nevus

A 41-year-old man presented with intermittent diplopia. Examination revealed mild, left sixth nerve palsy. MRI scan revealed a tumor involving the sphenoid sinus, clivus and cavernous sinus. Transphenoidal exploration and biopsy of the tumor was performed, and histology demonstrated malignant melanoma. Despite resection and radiation therapy, the patient died nine months later. An extensive blue nevus was present on the left side of his scalp, and on surgical exploration this extended intracranially as far as was explored. The histology of the brain lesion and the blue nevus were remarkably similar although cytologically, the brain lesion was more atypical. It was concluded that the brain lesion represented a metastasis or intracranial involvement from the blue nevus. Malignant blue nevus has been previously reported. This case is important because it draws attention to the possibility that extensive lesions involving the scalp may have intracranial involvement and may warrant aggressive management.