Test Details: Immunohistochemical testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody .It stains basal cells of prostate and basal / myoepithelial cells of breast and is used to rule out invasive malignancy. Useful for detecting benign breast proliferations (mosaic-like pattern) versus ductal carcinoma in situ (DCIS) (negative or rarely diffusely positive). Along with p63, it is used to detect squamous cell origin in poorly differentiated carcinomas