Malignant 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.
Review Date: 8/12/2009 Reviewed By: Jonathan Kantor, MD, North Florida Dermatology Associates, Jacksonville, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.