[Nasal cavity mucosal melanoma with skin extension mimicking a malignant lentigo with mucosal extension].

Mucosal melanoma is a rare malignant disease developed from melanocyte. We report the case of a patient with nasal cavity mucosal melanoma with a primary clinical and histological diagnosis of malignant lentigo with mucosal spreading. The presence of a c-Kit mutation, in a second lecture and the evolving nature of the lesion, reorientated the diagnosis of malignant lentigo to mucosal melanoma with skin extension. Extensive surgical resection and foramen free flap with costal graft reconstruction may have a local control of the disease. Yet, after one year, a regional evolution involving a parapharyngeal node was treated by stereotaxic radiotherapy. After 5 years, the patient was considered in clinical and radiological remission. Malignant lentigo with mucosal extension is a very rare situation, this diagnoses must be evoqued after setting mucosal melanoma diagnosis.