Neurofibromatosis 1 (NF1; previously known as von Recklinghausen disease) is an autosomal dominant genetic disorder with very high penetrance affecting about 1 in 3000 individuals. It is characterized by multiple café-au-lait spots, neurofibromas, and iris hamartomas (Lisch nodules). Other manifestations include: CNS lesions (optic nerve glioma, astrocytoma, heterotopias), skeletal abnormalities (osteolytic lesions resembling non-ossifying fibroma), vascular abnormalities (renovascular hypertension due to intimal proliferation), gynecomastia, non-neural tumors (pheochromocytoma, myelogenous leukemia), and GIST. Neurofibromas appear during childhood or adolescence as slow-growing painless lesions in virtually any body location. They may be of localized, plexiform, or diffuse types. Plexiform neurofibroma is virtually diagnostic of NF1.