This localized neurofibroma is composed of thick intersecting bundles of Schwann cells separated by myxoid stroma. Scattered mast cells and lymphocytes are present in the stroma. In the absence of neurofibromatosis 1, the risk of transformation to malignant peripheral nerve sheath tumor is unknown but is considered to be exceedingly small. Solitary neurofibromas are treated by simple excision. Lesions seen in the setting of Neurofibromatosis 1 are not amenable to surgical therapy due to their large numbers. Surgery is reserved for large, painful tumors or those impinging upon vital structures. Several agents have been tried for local control with some success, including cis-retinoic acid, interferon-alpha, and thalidomide.