Merkel cell carcinoma of skin: diagnosis and management strategies.

Merkel cell carcinoma (MCC) of the skin is a rare form of cutaneous malignancy of neuroendocrine origin with a propensity to affect predominately elderly patients in sun-exposed areas. The tumour has an extremely aggressive growth pattern with the potential to seed into the dermal lymphatics at an early stage as well as spread to nodes and distant sites. Successful outcomes can be achieved with early diagnosis and a multidisciplinary approach to management. Patients with MCC should be carefully staged to exclude distant metastatic disease. Treatment should be approached with both the primary site and the lymph nodes in mind. The primary site should be excised with clear margins, followed by postoperative radiotherapy to the primary site and affected nodes. Addition of chemotherapy to patients perceived to be at high-risk of distant recurrence (e.g. those with involved nodes) has been considered, but evidence supporting this approach is relatively scant. This treatment strategy needs to be approached with caution in the elderly because of the risk of myelosuppression. An aggressive treatment approach is warranted at the first attempt to treat MCC as treatment for recurrent disease is less likely to be successful.