HMB-45

HMB-45 is an antibody used in immunohistochemistry that recognizes a protein found in melanocytes. This protein is known as gp100, and it is involved in the production of melanin, the pigment responsible for skin color. HMB-45 is particularly useful in the diagnosis of melanoma, a type of skin cancer that originates from melanocytes.

Use in Diagnosis

HMB-45 is used in the diagnosis of melanoma because it is highly specific for melanocytes. This means that it will bind to melanocytes but not to other types of cells. When a tissue sample is stained with HMB-45, any melanocytes present will be highlighted, making them easier to identify under a microscope.

In addition to melanoma, HMB-45 can also be used to diagnose other conditions that involve melanocytes, such as pigmented nevi and blue nevi. However, it is not useful for diagnosing non-pigmented skin cancers, such as basal cell carcinoma and squamous cell carcinoma, because these cancers do not originate from melanocytes.

Limitations

While HMB-45 is a valuable tool in the diagnosis of melanoma, it is not perfect. Some melanomas do not express the gp100 protein and will therefore not be detected by HMB-45. Additionally, some benign lesions, such as Spitz nevi, can also express gp100, leading to false positive results.

See Also

• Melanoma
• Immunohistochemistry
• Antibody
• Melanocyte
• gp100