Neurofibromatosis (NF) is a group of three conditions in which tumors grow in the nervous system. The three types are neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis. In NF1 symptoms include light brown spots on the skin, freckles in the armpit and groin, small bumps within nerves, and scoliosis. In NF2 there may be hearing loss, cataracts at a young age, balance problems, flesh colored skin flaps, and muscle wasting. The tumors are generally non-cancerous.