Comparative study of cutaneous malignant melanoma according to anatomical site: plantar versus non-plantar melanoma.

Abstract

Plantar melanomas have more aggressive clinicopathological characteristics and higher mortality rates than melanomas in other anatomical regions. To compare clinicopathological features and define prognostic factors between melanoma in the plantar region and melanoma at other anatomical sites. A retrospective comparative analysis was conducted on all cutaneous melanoma patients seen at a tertiary referral center over 20 years. Patients were categorized into two groups: those with plantar melanoma and those with non-plantar melanoma. This study included 239 patients, comprising 186 patients with plantar melanoma (77.8%) and 53 with non-plantar melanoma (22.2%). Plantar melanoma was more common in males and older individuals and was associated with greater Breslow depth (p < 0.001), deeper Clark invasion (p < 0.001), and a higher incidence of ulceration (p = 0.02). Lymphovascular and visceral metastases were frequently observed in plantar melanoma patients (p = 0.013). Multivariate analysis indicated that Breslow thickness (p = 0.019), the presence of distant metastasis (p = 0.016), and lesions in traumatized areas (p < 0.001) were significantly associated with the plantar melanoma group. The plantar area should be considered a site associated with poor prognosis.