Neurofibromatosis and its Unusual Variants with Clinical and Histopathological Correlation - A Study in a Tertiary Care Centre

Introduction: Neurofibromatosis is an autosomal dominant genetic disease that affects ectoderm and mesoderm. The most common member of this group is neurofibromatosis 1, which varies in severity and has an incidence of 1 in 4000-5000. Plexiform neurofibromas have a 10% lifetime risk of developing peripheral nerve tumors. Changes in the cytomorphological and stromal features of neurofibromatosis lead to distinct histopathological features. Sometimes histopathological abnormalities and rare location may delay recognition of tumors (e.g. neurofibromas). Therefore, this study aims to elucidate the area of neurofibroma, and histomorphological and immunohistochemical studies as well as clinical examination may help diagnose the disease. Material and methods: Retrospective study of 26 cases was done over a period of 2 years. The cases of Neurofibromas were diagnosed with the help of H&E and immunohistochemical studies. Results: There were 14 men and 12 women. Age group was from 14 -70 years of age. In this study out of 26 cases, 65.38% cases were Sporadic lesions, 15.38% cases with Diffuse neurofibromas presented with multiple nodular lesions over the body with recurrence of lesions and had history of multiple hyperpigmented patch, cherry haemangioma, optic nerve atrophy, uveitis. 15.38% cases of Plexiform neurofibroma had familial association and were diagnosed on histopathological examination as Mixed type, Pigmented type and also presented at rare sites such as Vulva, Nose, Breasts. They were also associated with café au lait macules over neck, arm, buttock, thigh with axillary freckles and 1 case (3.84%) as Pacinian neurofibroma. Conclusion: The identification of areas of neurofibromatosis along with histomorphological and immunohistochemical study are helpful in management and proper treatment of the patients. Local and systemic examination of the patient to look for stigmata of NF1 and relevant family history is of the utmost importance.