Spinal neurocutaneous melanosis without cutaneous nevi

A case report of spinal neurocutaneous melanosis without cutaneous nevi.

To show a case and review the epidemiology, diagnosis and treatment of neurocutaneous melanosis without cutaneous nevi.

Neurocutaneous melanosis is a rare congenital syndrome consisting of benign or malignant melanocytic tumors of the central nervous system and cutaneous nevi. Symptomatic neurocutaneous melanosis has extremely poor prognosis, even in the absence of malignancy. Because leptomeningeal lesions of the neurocutaneous melanosis usually undergo malignant transformation, the life expectancy of almost all patients with malignant transformation is <1 year. In general, patients are treated with palliative therapy, such as shunt placement to reduce intracranial pressure or tumor resection to reduce compression of the brain or spine.

A 29-year-old man presented with marked hypesthesia and spastic gait. No skin abnormalities were evident. Magnetic resonance imaging (MRI) of the spine revealed intradural tumor at the T5 level. Computed tomography myelography showed intradural extramedullary tumor. Because symptoms progressed, he underwent surgery to decompress the spinal cord. After the pigmented dura was opened, a pigmented tumor was resected.

Histologically, the pigmented tumor represented low grade. The pigmented dura and bone comprised melanin-bearing cells without tumor cells. Meningeal melanocytoma with leptomeningeal melanosis in the absence of cutaneous nevi was diagnosed. Neurologic symptoms recovered immediately after surgery. No evidence of local recurrence has been seen after 3 years.

This patient displayed spinal meningeal melanocytoma and leptomeningeal melanosis without cutaneous nevi. The diagnosis in this case was speculated to represent a forme fruste of neurocutaneous melanosis.