MKI67 and acral lentiginous melanoma: Clinically, features such as BT, age, mitotic rate, ulceration, and tumor-infiltrating lymphocyte density have shown correlations with the result of SLNB in preliminary studies.5, 6, 7 However, few studies have focused on acral melanoma (particularly subungual morphology) and selected Ki67 proliferation index as a variable feature.