Acral Melanomas

Acral lentiginous melanoma is the most common histopathologic subtype in Asian. Histopathological features of acral lentiginous melanomas are characterized by continuous lentiginous spread of atypical melanocytes along the basal layer of the epidermis in melanoma in situ. Over time, melanoma cells invade into the dermis, developing vertical growth phase. We compared genetic changes comparing in situ and invasive acral lentiginous melanomas by next generation sequencing, found that markedly increased copy number gains of GAB2, PAK1, UCP2 and CCND1 are associated with melanoma invasion. Amelanotic acral melanoma is a diagnostic challenge. We also analysed the different metastasis patterns in amelanotic melanomas.