• All IHC stains will include a positive control tissue

• HMB45 reacts with most melanomas (approximately 80%) as well as with benign melanocytes such as in junctional melanocytes, Spitz nevi, and cellular blue nevi
• HMB45 is usually negative in desmoplastic and spindle cell melanomas
• HMB45 usually is nonreactive with normal melanocytes in normal adult skin, intradermal nevi, and melanophages
• For melanomas, order both S-100 and HMB45. If lesion is heavily pigmented, consider specifying the alkaline phosphatase (red) staining method
• No known reactivity with other carcinomas (false reports in literature regarding HMB45 positive breast carcinomas¹)
• Unique reaction of HMB45 in pulmonary lymphangiomyomatosis ² and angiomyolipomas³

Submit a formalin-fixed, paraffin-embedded tissue

Formalin-fixed, paraffin-embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications:

HMB45 recognizes a premelanosome glycoprotein

Staining pattern:

• Cytoplasmic based (may show focal/mosaic pattern in melanomas)

References

1. Bonetti et. al.: False-Positive Immunostaining of Normal Epithelial and Carcinomas with Ascites Fluid Preparations of Antimelanoma Monoclonal Antibody HMB-45; American Journal of Clinical Pathology; 95:454-459, 1991.
2. Bonetti, et. al.: Transbronchial Biopsy in Lymphangiomyomatosis; American  Journal of Surgical Pathology; 17(11):1092-1102, 1993. Sturtz, et. al.: Angiomyolipomas: The Nature and Expression of the HMB45 Antigen; Modern Pathology; 7(8):842-845, 1994.