Incidence and location of positive nonsentinel lymph nodes in head and neck melanoma

BACKGROUND: The complex lymphatic drainage in the head and neck makes sentinel lymph node biopsy (SLNB) for melanomas in this region challenging. This study describes the incidence, and location of additional positive nonsentinel lymph nodes (NSLN) in patients with cutaneous head and neck melanoma following a positive SLNB. METHODS: A retrospective review was performed using a single institution prospective database. Patients with a primary melanoma in the head or neck with a positive cervical SLNB were identified. The lymphadenectomy specimen was divided intraoperatively into lymph node levels I-V, and NSLN status determined for each level. RESULTS: Of 387 patients with melanoma of the head and neck who underwent cervical SLNB, 54 had a positive SLN identified (14%). Thirty six patients (67%) underwent immediate completion lymph node dissection (CLND) of whom eight patients (22%) had a positive NSLN. The remaining 18 patients (33%) did not undergo CLND and were observed. Half of positive NSLNs (50%) were in the same lymph node level as the SLN and 33% were in an immediately adjacent level; only two patients were found to have NSLNs in non-adjacent levels. The only factor predictive of NSLN involvement was the size of the tumor deposit in the SLN\u3e0.2 mm (p = 0.05). Superficial parotidectomy at CLND revealed metastatic melanoma only in patients with a positive parotid SLN. CONCLUSIONS: A positive NLSN was identified in 22% of patients undergoing CLND after a positive SLNB. The majority of positive NSLNs are found within or immediately adjacent to the nodal level containing the SLN