Yoo H, Kim H, Kwon ST, et al. - Since subungual melanoma (SUM) has a poor prognosis due to delayed diagnosis, but the progression, consensus on surgical treatment, correlation with clinical outcomes remains unknown, researchers conducted this retrospective review to identify the pattern of dermal invasion in different locations of the nail apparatus and its association with prognosis. Between January 2011 and April 2019, surgically treated SUM patients were analyzed. Because of its strong association with invasion depth, metastatic progression, and disease-free survival, hyponychial invasion is an important prognostic predictor of SUM. Patients with hyponychium invasion should be evaluated, treated, and monitored more closely.