Cranial nerve outcomes in regionally recurrent head & neck melanoma after sentinel lymph node biopsy.

OBJECTIVE: Characterize long-term cranial nerve (CN) outcomes following sentinel lymph node biopsy (SLNB) based management for head and neck cutaneous melanoma (HNCM). METHODS: Longitudinal review of HNCM patients undergoing SLNB from 1997-2007. RESULTS: Three hundred fifty-six patients were identified, with mean age 53.5 ± 19.0 years, mean Breslow depth 2.52 ± 1.87 mm, and 4.9 years median follow-up. One hundred five (29.4%) patients had SLNB mapping to the parotid basin. Eighteen patients had positive parotid SLNs and underwent immediate parotidectomy / immediate completion lymph node dissection (iCLND), with six possessing positive parotid non-sentinel lymph nodes (NSLNs). Fifty-two of 356 (14.6%) patients developed delayed regional recurrences, including 20 total intraparotid recurrences: five following false negative (FN) parotid SLNB, three following prior immediate superficial parotidectomy, two following iCLND without parotidectomy, and the remaining 12 parotid recurrences had negative extraparotid SLNBs. Parotid recurrences were multiple (4.9 mean recurrent nodes) and advanced (n = 4 extracapsular extension), and all required salvage dissection including parotidectomy. Immediate parotidectomy/iCLND led to no permanent CN injuries. Delayed regional HNCM macrometastasis precipitated 16 total permanent CN injuries in 13 patients: 10 CN VII, five CN XI, and one CN XII deficits. Fifty percent (n = 10) of parotid recurrences caused ≥1 permanent CN deficits. CONCLUSIONS: Regional HNCM macrometastases and salvage dissection confer marked CN injury risk, whereas early surgical intervention via SLNB ± iCLND ± immediate parotidectomy yielded no CN injuries. Further, superficial parotidectomy performed in parotid-mapping HNCM does not obviate delayed intraparotid recurrences, which increase risk of CN VII injury. Despite lack of a published disease-specific survival advantage in melanoma, early disease control in cervical and parotid basins is paramount to minimize CN complications. LEVEL OF EVIDENCE: 4 (retrospective case series) Laryngoscope, 2019.