An unusual cutaneous malignant melanoma arised de novo: a case report.

Malignant melanoma is a type of skin cancer with accelerated evolution and a high metastatic potential, thus being the most aggressive type of skin tumor. Its origin resides in the epidermal melanocytes, which multiply chaotically, therefore becoming malignant cells. The main objective of this study was represented by the clinical, histological and also immunohistochemical analysis of a peculiar case of malignant cutaneous melanoma arised de novo. Patient M.H., age 54, was admitted due to concerns regarding a cancerous growth on the right scapula. Dermoscopy revealed an asymmetrical, polymorphic and polychromatic lesion; therefore, a surgical intervention was scheduled. The histological exam showed a microscopic structure resembling an epithelioid cell malignant melanoma, with inflammatory reaction and central ulcerations. Immunostaining with melanocytic differentiation markers revealed the presence of pagetoid-disseminated cancerous cells into the epidermis, in addition to deep dermis invasion and the extension of cancerous cells in and around the hair follicles. In most cases, malignant melanoma develops on pre-existent nevi, but it can also appear de novo with accelerated evolution, mainly at phototype I young people. The importance of this particular case consists in the fact that the tumors presented some unusual particularities: appearing on healthy skin tissue, with slow evolution, at an age when this pathology is rarely encountered; the patient was phototype III and the cutaneous territory had been rarely exposed to ultraviolet radiations. Therefore, the case has proven interesting and worthy of being taken into consideration by the appropriate literature.