Diagnosis and management of merkel cell carcinoma of the head and neck: current trends and controversies.

Merkel cell carcinoma is an aggressive neuroendocrine cutaneous malignancy with a predilection for regional and distant metastasis. This malignancy presents most commonly on the head and neck of elderly Caucasian males, with a higher prevalence in the immunosuppressed. A high index of suspicion must be maintained due to the often asymptomatic presentation. Lip tumors, scalp tumors, local invasion, nodal metastasis, distant metastasis, and lymphovascular invasion are poor prognostic factors. Up to 8.7% of patients present with distant metastasis, and PET-CT is an accurate staging tool with a 90% sensitivity. Combined aggressive surgical resection with adjuvant radiotherapy affords the best regional control rates. The regional lymphatics must be addressed with either sentinel lymph node biopsy, surgery, or elective radiation due to the risk of occult metastasis. Addition of chemotherapy has no proven benefit in locoregional control.