Melanoma markers-negative primary melanoma with melanoma markers-positive metastasis.

Concordant loss of all 3 commonly used melanocytic markers (ie, S-100, HMB-45, and Melan-A) in a primary malignant melanoma with expression of the same in the metastatic lesion is very rare. To the best of the authors' knowledge, they documented the second case of this unusual and rare phenomenon.