OverviewMalignant melanoma is the most dangerous type of skin cancer. Melanomas beneath the fingernail appear as a black or bluish black discoloration. This type of malignancy spreads (metastasizes) readily.
Update Date 1/31/2016
Updated by: Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.