Margins of excision and prognostic factors for cutaneous eyelid melanomas.

Background: Guidelines for wide excision of cutaneous melanomas according to Breslow thickness are impractical when considering melanomas arising on eyelid skin. No consensus exists regarding appropriate excision margins for these tumours. This study sought to determine whether excision margins influenced locoregional recurrence, and to identify prognostic factors for survival in these patients.

Methods: Fifty-six cases of invasive cutaneous eyelid melanomas diagnosed between 1985 and 2011 were identified from the database of Melanoma Institute Australia. Clinical and pathological factors were assessed for their associations with recurrence and survival.

Results: Local recurrence occurred in 12 patients (21%), nodal metastasis in 6 (11%) and distant metastasis in 2 (4%). Pathological margins>2 mm from the in situ component of the tumour were associated with increased disease-free survival (P=0.029) compared with margins≤2 mm but there was no statistically significant benefit for a pathological margin>2 mm from the invasive component. Lower eyelid melanomas were found to have a significantly higher local recurrence rate than upper eyelid melanomas (P=0.044).

Conclusions: This series of cutaneous eyelid melanomas is the largest yet reported. The results suggest that, as a minimum, an in vivo surgical margin of 3 mm (corresponding to a 2 mm pathological margin after tissue fixation) is desirable for eyelid melanomas. We recommend a surgical excision margin of 3 mm for eyelid melanomas≤1 mm in Breslow thickness. However, for melanomas>1 mm in thickness, the current practice of aiming to achieve 5 mm margins would seem reasonable. Patients with lower eyelid melanomas warrant particularly close follow-up given their higher local recurrence rate.