Evaluation of Phenotypic Characteristics of 53 Cases of Neurofibroma in Hazrat Fatemeh Hospital during the Years 1994-2005

Background and Objective: Neurofibromas occur as solitary and multiple forms. The solitary ones are extraneural and more common, histologically exhibiting spindle cells with wavy nuclei, scattered among collagen fibers. Multiple neurofibromas are seen in neurofibromatosis (types I and II), including intraneural (plexiform, cutaneous deep circumscribed) and extraneural (cutaneous, deep diffuse) variants and various combinations of the above mentioned forms. In reviewed literature, solitary localized neurofibromas are mentioned to affect the genders equally, most develop in persons between the ages 20 and 30 years and evenly distribute over the body surface. Since Hazrat Fatemeh hospital is the referral center of dermatology, it seemed that evaluation of patients with neurofibroma within 11 years could be helpful. Materials and Methods: The present study included 53 patients with neurofibromas who referred to department of pathology of Hazrat Fatemeh Hospital during the years 1994-2005. Their lesions were diagnosed as neurofibromas by the pathologist. Lesions were categorized into solitary or multiple neurofibromas, then sex and age distributions and the involved areas were compared in each group. Results: In solitary group, neurofibromas were distributed in order of frequency over face (48%), upper extremities (13%), scalp, trunk, and lower extremities each one 9%, and neck (4%). The frequencies of distribution for neurofibromatosis were face (40%), upper extremities (23%), trunk, and lower extremities each one 14%, and scalp and neck each one 6%. Solitary neurofibromas of face, trunk, and upper extremities predominated in females, but lesions of scalp, neck, and lower extremities were more common in males. In contrast, neurofibromatosis of face, scalp, and neck were more frequent in males, the reverse was true for lesions of trunk and extremities. The peak incidence of solitary neurofibroma was within the ages of 15 and 30 years. In comparison, the peak incidence of neurofibromatosis was between 9 and 13 years. One third of neurofibromatosis developed plexiform neurofibromas, but no single case was observed in solitary group. None of the solitary or multiple neurofibromas were transformed to malignancy up to the time of current study. Conclusion: The solitary neurofibromas of head (p<0.04) and multiple neurofibromas of face (p= 0.04) were more prevalent in males, while multiple neurofibromas of upper extremities (p<0.03) were more frequent in females. Age distribution of solitary neurofibromas as compared to references and lower incidence age of neurofibromatosis in the study were in concordance with references.