Immunohistochemical examinations of a patient shows positive for HMB 45. She may have:

S-100 and HMB-45 are commonly used tumor markers for melanoma. Select Immunohistochemical Stains: Immunohistochemical Stain Neoplasms that Stain Positive Cytokeratin Carcinomas Desmin Benign and malignant neoplasms of smooth and skeletal muscle Glial fibrillary acidic protein (GFAP) Astrocytomas HMB-45 Melanoma *-Fetoprotein (AFP) Hepatocellular carcinoma, yolk sac tumor Chromogranin A Small cell carcinoma Ref: Wyatt C., Kemp W.L., Moos P.J., Burns D.K., Brown T.G. (2008). Chapter 20. Dermatopathology. In C. Wyatt, W.L. Kemp, P.J. Moos, D.K. Burns, T.G. Brown (Eds), Pathology: The Big Picture.