Cutaneous neurofibroma. Light micrograph (LM). Neurofibroma of skin is a common, benign tumour that appears as a small bump on the skin. It is a nerve tumor (neurofibroma) that arises from the nerves underneath the skin surface, or subcutaneously. The risk factors and cause of development of neurofibroma of skin is unknown. In some cases, multiple tumours may indicate the presence of neurofibromatosis type 1 (NF-1), while solitary tumours are not associated with this genetic disorder. The prognosis is excellent on removal of the neurofibroma of skin, since it is a benign tumour. Magnification: X 40 when printed at 10 centimetres wide.