495 Clinicopathologic Characteristics of Trauma-Related Nail Apparatus Melanoma: A Comparative Study According to the Presence of Trauma Prior to Melanoma Development

Nail apparatus melanoma (NAM) is a subtype of cutaneous occurring at nail units and belongs to the acral lentiginous subgroup. Due its unique anatomical structure protect site, mechanical trauma may have clinicoprognostic impact on NAM. Therefore, we investigated histopathological characteristics NAM according presence history prior development. Clinicopathological follow-up data patients with were obtained. We included 87 NAM, 21.8% whom had previous history. Trauma-related NAMs more likely involve toenail (p = 0.040), include high proportion amelanotic melanomas 0.038) as well bed tumor 0.013), longer time interval between onset change confirmed diagnosis 0.012). Moreover, survival analysis revealed that trauma-related frequently showed progression in general 0.034) nodal metastasis 0.047) worse prognosis terms free 0.004). In conclusion, characteristics. The specific clinicopathological features indicate play role