On gross appearance, a neurofibroma is a firm, gray-white mass with no capsule. They vary in size from a few millimeters to four to five centimeters. Microscopically, neurofibromas are made of interlacing bundles of elongated cells. These cells are bland and disorderly with intracellular collagen strands. Neurofibromas have variable S-100 expression and nerve fibers should be present.
Solitary neurofibromas are well delineated and firm lesions that are white and shiny in appearance.
Plexiform neurofibromas are diagnostic of von Recklinghausen's disease. Close follow up of these patients is necessary due to the high rate of malignant transformation. Treatment, if necessary, is surgical excision. Cotran, Robbins and Kumar, Robbins Pathologic Basis for Disease , W.B. Saunders, Co., 1994. Treatment and Prognosis , W.B. Saunders, Co., 1991.