Head and neck melanoma present a unique problem in terms of complex anatomy and atypical nodal basin drainage which makes sentinel lymph node biopsy challenging and obtaining wide surgical margins difficult. 25-35% of invasive melanoma are seen in the head and neck region. The purpose of this study was to evaluate surgical margins and other prognostic factors determining the oncological outcome of patients with invasive head and neck melanoma.

Electronic and paper records of a historical cohort of 347 patients with invasive head and neck cutaneous melanoma seen in the province of Manitoba during 1997-2012 and treated with radical intent with a median follow up of 6 years. Information on tumor stage, margin status, treatment and pathological details, modality was collected. Disease free survival (DFS) and disease specific survival (DSS) were calculated by Kaplan Meir method and analyzed by Cox Proportional hazard model for independent variables using SPSS 22.0.

Mean age of the patients at diagnosis was 65.6 + 17.6 years and 63.5% of the patients were female.  59.6% of the patients had Stage I, 28.7% stage II, 9.0% stage III and 2.8% stage IV invasive melanoma. All patients underwent surgical resection and 55 out of 70 T2 invasive melanoma patients underwent sentinel node biopsy and 11(20%) had positive sentinel nodes. DSS at 5 years was 75% at 5 years and 66.7 at 10 years. Age of the patient at diagnosis (p=0.047) and stage of disease (p<0.001) had significant independent impact on DSS.  Margin of resection did not have any significant influence on either DSS (p=0.347) or DFS (p=0.348). There was no difference in the oncological outcome of 124 patients with 1-4 mm thick invasive head and neck melanoma excised with 1 cm or 2 cm margin.

TNM stage and age of diagnosis were independent prognostic factors determining the oncological outcome of invasive melanoma of head and neck region. There was no difference in oncological outcome of 1-4mm thick melanoma excised with 1 or 2 cm margin.