Rapidly fatal metastatic melanoma arising from a congenital nevus in a young female

Abstract

Melanoma is an aggressive and potentially fatal tumor of melanocytic origin. It may occur at any age yet more rarely at a young age. Melanomas in young patients have overall a more favorable prognosis than in older. However, progression to the metastatic stage and the death of the patient are not exceptional. One of the major risk factors for the development of melanoma in children and young adults is the congenital melanocytic nevus (CMN) [3]. The risk of malignant transformation of all congenital nevi ranges from 0.05% to 10.7%. The risk of malignant degeneration is correlated with size and location [4]. The size of the CMN above 40 cm as well as the presence of satellite nevi and the location in the trunk seem to increase the risk of developing MM. The role of surgical removal in inducing melanomas is controversial. In anatomopathology, melanomas arising from CMNs are usually located in the dermis and hypodermis, while melanocytic proliferation in a melanoma without a CMN starts in the epidermis [3]. Given the differences in the anatomical involvement of the disease, melanoma arising from congenital nevi may be considered a separate entity from the conventional case of melanoma and management may differ. Large excision may not be sufficient to remove all neoplastic cells from the nevi, and adjuvant aggressive systemic therapies may be essential to avoid a fatal outcome. A recent study revealed that congenital nevi preferentially harbor NRAS mutations rather than BRAF mutations commonly seen in other types of nevi, indicating an altered molecular basis of nevogenesis in congenital nevi. Herein, we report the case of a rapidly fatal metastatic melanoma in a young female arising from a congenital nevus of the trunk.