Clinical and histopathological characteristics of melanomas in Asians under age 40.

Previous studies suggested racial difference between young melanomas of Caucasians and non-Caucasians. This study aimed to elucidate characteristics of melanomas in young Asians. We analyzed clinical and histologic characteristics of patients under age 40 diagnosed with cutaneous melanomas including in situs. Survival and subgroup analyses were conducted. Among the 45 patients investigated, the most common anatomical sites of melanomas were lower extremities (22/45, 45.3%) and acral lentiginous type was the most common histological variety (18/45, 40%), of which 12 were subungual type. Lymph node involvement and nodular histologic type were significant prognostic factors. Age subgroup analysis revealed that clinical and histopathologic features of adolescents (15-21 years old [YO]) were distinct from those of young adults (22-39 YO), but similar to children (0-14 YO) who showed amelanotic nodules (p < 0.01) and spitzoid subtypes (p < 0.001). Pediatric melanomas (< 20 YO), showed racial differences based on sex (p < 0.01), an-atomical site (p < 0.001), histologic types (p < 0.001), and lymph node involvement at diagnosis (p < 0.047). Understanding the differences among age groups will help clinicians decide management of melanomas in young Asian patients.