SUMMARY, EXPLANATION AND LIMITATIONS:
Calponin (34 kDa polypeptide) is a cytoskeleton-associated actin-binding protein that interacts with tropomyosin and calmodulin. Calponin has been reported to be highly specific for normal and neoplastic myoepithelium and a valuable diagnostic aid in the differential diagnosis involving polymorphous low-grade adenocarcinoma, adenoid cystic carcinoma, and pleomorphic adenoma of the salivary gland. Myoepithelial markers can also help in differentiating papilloma from papillary carcinoma of the breast especially with a panel of CK5/6, p63, and neuroendocrine markers (chromogranin A and synaptophysin). Calponin together with basal lamina markers (laminin and type IV collagen) are useful in differentiating microinvasive from ductal carcinoma in situ (DCIS) of the breast.
Immunogen: Crude human uterus extract.
Staining pattern: Cytoplasmic.
Positive control: Tissue sample from uterus or breast.
This antibody is designed for the specific localization of human calponin using IHC techniques in formalin-fixed, paraffin-embedded tissue sections.
Detection was performed in cells of the aortic tunica media of adult (not in the fetal) in myoepithelial cells of benign breast lesions and malignant lesions.
Also reacts with epithelial cells of breast papillomas, but no reactivity was observed in intracystic papillary carcinomas. Identifies myoepithelial cells surrounding the ducts and lobules and ductal carcinomas in neoplastic myoepithelial cells of pleomorphic adenomas of salivary glands.