<unk>  is a congenital disorder characterized by the presence of congenital melanocytic nevi on the skin and melanocytic tumors in the leptomeninges of the central nervous system. These lesions may occur in the amygdala, cerebellum, cerebrum, pons and spinal cord of patients. Although typically asymptomatic, malignancy occurs in the form of leptomeningeal melanoma in over half of patients. Regardless of the presence of malignancy, patients with symptomatic<unk>  generally have a poor prognosis with few treatment options. The pathogenesis of<unk>  is believed to be related to the abnormal postzygotic development of melanoblasts and mutations of the NRAS gene.
Neurocutaneous melanosis
Nevus anemicus
Phakomatosis pigmentokeratotica
Granulomatous slack skin
Blue nevus
Erythema dyschromicum perstans
Sparganosis
Hypertrichosis cubiti