[A new variety of neurocutaneous melanosis: benign leptomeningeal melanocytoma associated with extensive Mongolian spot on the back].

A 38-year-old Japanese man presented with a blue macule on the back. A spinal meningeal tumor at the C3-C5 levels was detected radiologically and excised. The histological findings in the biopsy specimen from the blue macule were consistent with an extensive Mongolian spot. The histological diagnosis of the meningeal tumor was benign melanocytoma. The case was thought to be a new variety of neurocutaneous melanosis.