Proximal nail plate destruction in subungual melanoma could be a possible predictor of invasiveness thicker than 1.25 mm.

Various patterns of nail plate destruction are common features in subungual melanoma ( SUM), but there has been no reports regarding their clinical significance according to the pattern of nail plate destruction in terms of tumor thickness. We tried to find a relationship between dermal invasion of SUM and proximal nail plate destruction ( PNPD). Clinical information of patients with SUM was reviewed retrospectively from seven dermatology training hospitals in Korea. The PNPD was defined as a visible loss of full thickness of nail plate touching the eponychium at the most proximal part of it. We evaluated whether there are correlations between patients' age, sex, location of SUM, Breslow thickness ( BT) and the presence of PNPD. Among 93 patients with SUM, 36 (38.7%) showed PNPD. Sex and BT showed significant correlations with the presence of PNPD in univariate analysis ( P < 0.05). BT, age and sex showed significant correlations with the presence of PNPD in multivariate analysis ( P < 0.05). Among them, BT showed the strongest correlation with the presence of PNPD (area under the curve, 0.722) and the cut-off value was 1.25 mm. In conclusion, we suggest that PNPD in SUM could be a possible predictor of invasiveness of more than 1.25 mm BT. [ABSTRACT FROM AUTHOR]