Ema

Acronym for "epithelial membrane antigen."

An antigen that forms part of a group of glycosylated proteins molecular weight (259 - 400 kD), which is detectable on a large number of epithelia and occurs in milk fat. The antigen is also known as human milk fat globulin.

Antibodies against the epithelial membrane antigen are used in histopathology to differentiate less differentiated epithelial tumors (see literature). Squamous cell carcinomas of the surface epithelium stain with EMA (the normal epidermis shows no reactivity). EMA is often used in parallel with cytokeratin antibodies or CEA antibodies. The antibody can cross-react in CD30-positive anaplastic large cell lymphomas.

Sajin M et al (2014) Trichilemmal carcinoma - a rare cutaneous malignancy: report of two cases. Rome J Morphol Embryol 55:687-691