Neurocutaneous melanocytosis with tardive onset neurological manifestation

Neurocutaneous melanocytosis is a rare syndrome consisting of multiple/giant congenital melanocytic nevi (CMN) and leptomeningeal pigment cell tumors. An error in morphogenesis in the neural ectoderm is thought to be its primary etiology. We report a case of a 47-year-old male patient with multiple CMN associated with adult-onset (rare presentation) seizures, hydrocephalus, and a meningeal mass consistent with leptomeningeal melanoma on radiology and histopathology.