Merkel cell carcinoma: a review and update on aetiopathogenesis, diagnosis and treatment approaches

Merkel cell carcinoma (MCC) or primary cutaneous neuroendocrine carcinoma is a relatively uncommon form of skin cancer. It is an aggressive neoplasm with high tendency for local recurrence and lymph node and distant metastasis, whose incidence has been rising in the last 2 decades. A novel polyomavirus (MCPyV) has been found in a significant proportion of MCCs, and this finding significantly contributed to the understanding of its pathogenesis. It is fairly consensual at the current state of know-ledge that appropriate staging, including sentinel lymph node biopsy, is very important in order to plan adequate treatment. Treatment includes aggressive surgery of the primary tumour and lymph node basin, commonly combined with adjuvant radiotherapy. Chemotherapy is usually reserved for distant metastasis. In the present article, the authors review the current knowledge about MCC with special emphasis on the new pathogenetic findings and current recommendations regarding management.