Malignant melanoma keratin

Miettinen M, Franssila K. Immunohistochemical spectrum of malignant melanoma the common presence of keratins. Lab Invest. 1989 61 623-628. 

PSA has been found to stain scattered tumor cells from cutaneous malignant melanoma and its metas-tases." This should not create a diagnostic dilemma because prostate cancers are strongly and diffusely positive with LMW keratin antibodies such as CAM5.2, which is another illustration of the necessity of examining tumors with a panel of antibodies. 

As known by most surgical pathologists, malignant melanomas may show significant variability in differentiation. Nearly all show immunostaining for S-100 protein and vimentin. Approximately 50% immuno-stain for human melanoma black-45 (HMB-45) antigen. Most stain for pan melanoma antibody. Rare melanomas immunostain for keratin, " which can cause diagnostic confusion. 

---