Clinicopathologic Characteristics of Trauma-Related Nail Apparatus Melanoma: A Comparative Study according to the Presence of Trauma prior to Melanoma Development

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