Excision Depth and Prognosis in T1-T3 Plantar Melanoma: Is Complete Excision of Plantar Fat Pad Necessary?

BACKGROUND

While peripheral excision margins in cutaneous melanoma are well established, the optimal excision depth remains unclear. In plantar melanoma, the fat pad plays a key functional role, raising concerns about whether full excision is necessary for thin and intermediate-thickness lesions. This study evaluated the association between excision depth and oncologic outcomes in T1-T3 plantar melanoma.

METHODS

Patients with primary T1-T3 plantar melanoma who underwent wide excision between 2008 and 2022 were reviewed. They were grouped by excision depth: intra-adiposal (partial fat pad preservation) and suprafascial (complete removal). Oncologic and functional outcomes, assessed via the Foot Function Index (FFI), were compared.

RESULTS

Ninety-four patients (40 intra-adiposal, 54 suprafascial) were analyzed (median follow-up, 43 months). Tumor-free margins were achieved in all cases. Baseline characteristics were similar, except for lesion location. Recurrence rates were comparable, and excision depth was not significantly associated with recurrence-free survival. FFI scores from 26 patients (13 per group) tended to be better in the intra-adiposal group, though not statistically significant.

CONCLUSIONS

In thin to intermediate-thickness plantar melanoma, intra-adiposal excision may be oncologically safe if tumor-free margins are achieved, potentially offering functional benefits without compromising oncologic outcomes.