What does HMB-45 positive mean?

HMB-45 is a monoclonal antibody that reacts against an antigen present in melanocytic tumors such as melanomas, and stands for Human Melanoma Black. It is used in anatomic pathology as a marker for such tumors. The specific antigen recognized by HMB-45 is now known as Pmel 17.

What does HMB-45 stain?

HMB-45 is a widely used immunohistochemical stain for detection of primary as well as metastatic melanoma (1). Presumably, this method uses monoclonal antibodies to a glycoprotein that is present in premelanosomes (11).

Can nevus progress to melanoma?

Nevi may also be important as potential precursors of melanoma; however, most nevi are stable and will not progress to malignancy.

What kind of lesions are positive for HMB-45?

Such lesions may be positive for HMB-45, or retest as positive using monoclonal and polyclonal antibodies against S100 protein. 1933 S100 protein is also found in nevi and Langerhans cells, as well as cutaneous neural tumors.

Where is HMB-45 expressed in a melanoma cell?

HMB-45 can be expressed in the intraepidermal component of compound nevi and superficial stromal melanocytes 49 but is largely negative in the subepithelial component in comparison to malignant melanoma. Malignant melanoma usually shows diffuse HMB-45 staining with increased atypical melanocytic cells in cycle with Ki-67 staining.

What is the definition of nevus flammeus birthmark?

Nevus flammeus (Concept Id: C0235752) A congenital vascular malformation in the skin (birthmark) characterized by the presence of dilated capillaries. The affected area of the skin is flat and reddish-purplish in color. Nevus flammeus MedGen UID: 65911 •Concept ID: C0235752 Congenital Abnormality Synonyms: Nevus simplex; port-wine stain

What are the symptoms of nevus flammeus Orphanet?

Follow this link to review classifications for Nevus flammeus in Orphanet. A genetic syndrome caused by abnormalities in chromosome 11. It is characterized by large birth weight, macroglossia, umbilical hernia, ear abnormalities, and hypoglycemia.