Lymphatic drainage patterns of head and neck cutaneous melanoma: does primary melanoma site correlate with anatomic distribution of pathologically involved lymph nodes?

The aim of this study was to analyse patterns of metastatic spread from cutaneous head and neck melanoma, which are said to be highly variable. The medical records of 145 patients with pathologically proven metastatic melanoma were reviewed retrospectively. The location of pathologically positive lymph nodes was compared with clinically predicted spread, and patients with metastatic disease in areas outside of predicted drainage patterns were considered aberrant. There were 33 curative and 73 elective neck dissections. 21 of 77 patients undergoing parotidectomy had positive results for metastases. Clinical prediction proved to be correct in 33 of 45 cases (73.3%). Two patients with lateralized melanomas were initially seen with contralateral metastases. Six of 45 patients (13.3%) developed contralateral metastases after neck dissection. Patients with clinical involvement of the parotid gland were at high risk of occult neck disease (40%). Patients undergoing neck dissection for primaries originating in face, forehead, coronal scalp, periauricular area, and upper neck should be considered for parotidectomy. Patients with posterior scalp and posterior neck primaries should be considered for selective neck dissection in conjunction with posterior lymphadenectomy. In patients with coronal scalp and periauricular primaries, a complete neck dissection including parotidectomy is the recommended approach.