Melanoma Arising From a Pre-existing Neurofibroma in a Patient With No Prior Diagnosis of Systemic Neurofibromatosis 1 or 2: A Case Report

The pathophysiology of melanoma involves malignant transformation of melanocytes. These can arise de novo or result from malignant transformation of a pre-existing nevus. This case report presents a patient with a new pigmented lesion, arising from a pre-existing neurofibroma, on her left scapula and no personal or family history of systemic neurofibromatosis. Biopsy confirmed the lesion to be malignant melanoma and, after excision, postoperative pathology showed a pre-existing neurofibroma. A review of the literature suggests there may be a link between the pathogenesis of neurofibroma and malignant melanoma, because NF1 mutations are observed in both neurofibromatosis and malignant melanoma. We hypothesize that the pre-existing neurofibroma created a proliferative environment that gave rise to the adjacent neoplasm. Further research is required to understand the shared pathway, because this may lead to novel forms of surveillance and treatment.