Clinicoprognostic characteristics of cutaneous metastatic melanoma: a retrospective comparative study between acral and nonacral melanoma

Background Although cutaneous melanoma has been widely evaluated, data elucidating the clinical features and prognostic factors of cutaneous metastatic melanoma are limited. Objective To determine and compare the clinicoprognostic features of cutaneous metastasis in acral and nonacral melanoma. Methods The Asan Medical Center database was reviewed for cases of cutaneous metastatic melanoma that had been confirmed by skin biopsy between January 1996 and December 2017. Results Cutaneous metastasis occurred in 12.4% (61 of 492 cases) of our cohort. The frequency of cutaneous metastasis was higher in nonacral melanoma than that in acral melanoma. The mean duration between the initial diagnosis of a primary tumor and cutaneous dissemination was 19.8 months. Cutaneous metastasis developed earlier during the disease course in acral melanoma than that in nonacral melanoma. Cutaneous metastasis was more disseminated, involving multiple anatomy sites in nonacral melanoma than that in acral melanoma. In-transit metastasis was significantly more common in acral melanoma than that in nonacral melanoma. The disease stage at the time of cutaneous metastasis was not significantly different between acral and nonaral melanoma. In-transit metastasis was commonly associated with visceral involvement in acral melanoma but not in nonacral melanoma. The extent and multiplicity of cutaneous metastasis were dependent on the status of other viscera during the cutaneous metastasis. No significant difference in survival during the cutaneous metastasis was observed between acral and nonacral melanoma. Conclusion Clinicoprognostic features of cutaneous metastasis were different between acral and nonacral melanoma.