Estrogen Receptor Positive by Immunohistochemistry Greater than or Equal to 50 Percent

**Semantic type:** Laboratory or Test Result

**Definition:** An immunohistochemical staining finding indicating that greater than or equal to 50 percent of the cells in a sample are expressing estrogen receptor.

**Synonyms:** - ER >=50% by IHC - ER Staining by Immunohistochemistry >= 50% - Estrogen Receptor Positive by Immunohistochemistry Greater than or Equal to 50%