Melanoma arising in a cervical spinal nerve root: report of a case with a benign course and malignant features.

A 20-year-old caucasian woman with a 5-year history of right arm, neck, and back pain sought treatment when an automobile accident (4 months before admission) exacerbated her pain. Magnetic resonance imaging revealed an intra- and extradural mass compressing the spinal cord at the C5-C6 level. It also extended into and widened the neural foramen, mimicking a neurofibroma. A single cafe-au-lait spot was discovered in the inguinal region. A two-staged surgical resection was performed on an apparent hemorrhagic C6 nerve root mass. The mass exhibited diagnostic features of a malignant melanoma histologically, immunocytochemically, and ultrastructurally. A search for a primary lesion outside the nervous system or other metastases during an 8-year period from the onset of symptoms has been negative. The patient's chronic history, evidence of neural foraminal enlargement, and the absence of other malignant melanoma lesions or subsequent metastases indicates that this lesion may be a primary melanoma of the nerve root with a benign course.