The metastatic potential of head and neck cutaneous malignant melanoma: is sentinel node biopsy useful?

Results from a large multicentre trial suggest that sentinel lymph node biopsy examination may benefit disease-free survival in patients with cutaneous malignant melanoma of intermediate thickness, but this is controversial. We recorded the outcomes of patients with these lesions in the head and neck with specific reference to regional lymph node metastases, to find out whether routine sentinel lymph node biopsy examination would have been beneficial. We reviewed pathology databases, multidisciplinary outcomes, and notes for all patients managed by a regional melanoma service between 2004 and 2009, and recorded key characteristics of the tumours. Details on patients with malignant melanoma of intermediate thickness (1.2-3.5mm) were further analysed for the development of nodal metastases in the neck over a 3-year postoperative period. We compared our data with the rate of predicted nodal metastases generated from the trial. Of 132 patients with malignant melanoma of the head and neck, 33 (25%) had lesions of intermediate thickness, and nodal metastases developed in only one. The remaining 32 remained free of neck disease during the study period. Although trial data predicted that 16% (n=5 in this sample) would show signs of metastasis and require neck dissection, on the basis of our data, practice in our unit will not change. Sentinel node biopsy examination for melanoma remains controversial because the natural history of metastatic spread of disease is not fully understood.