Skin metastases of malignant melanoma: a clinical and prognostic survey.

Skin metastases are a frequent event in the natural history of malignant melanoma, both in the early and late phases of disease progression. In this study, we reviewed our database of 4865 melanoma patients, who were diagnosed and followed up prospectively over a 30-year period at our institution. Statistical analyses were focused on patients with secondary involvement of the skin. Seven hundred and thirty-three of the 4030 patients that met the inclusion criteria (18.2%) developed cutaneous metastases; the skin was involved as first site in 413 patients (56.3%) and after regional lymph node spreading in 208 (28.4%) patients. In a lower number of patients, cutaneous metastases developed only in advanced stages of the disease. Skin metastases were mainly locoregional, when arising as the first site of relapse (89.3%) and/or in patients with a primary melanoma of the lower limbs; in contrast, disseminated metastases are more often observed after a visceral involvement and for primary melanomas of the trunk. Moreover, despite a lower disease-free survival rate (1.3 vs. 2.9 years), we showed a significantly longer time to progression to visceral involvement for the group of patients with cutaneous locoregional metastases (62.5 vs. 17.8 months). The site of primary melanoma is strictly related to the pattern of cutaneous recurrence. The disparity in clinical outcome between patients with locoregional or disseminated skin metastases should therefore be taken into consideration in their management.