Research Artilce Open Access Journal of Molecular Biomarkers & Diagnosis J o u r n a l o f M o l e c u l a r B i o m a r k e r s & D i a g n o s i s ISSN: 2155-9929 Abdallah and MF El Deeb, J Mol Biomark Diagn 2017, 8:4 DOI: 10.4172/2155-9929.1000342 Volume 8 • Issue 4 • 1000342 J Mol Biomark Diagn, an open access journal ISSN:2155-9929 *Corresponding author: Dina M Abdallah, Assistant Professor of Pathology, Alexandria Faculty of Medicine, Egypt, Tel: +2034862506; E-mail: dinabdalla@yahoo.com Received March 31, 2017; Accepted April 28, 2017; Published April 30, 2017 Citation: Abdallah DM, MF El Deeb N (2017) Comparative Immunohistochemical Study of P63, SMA, CD10 and Calponin in Distinguishing In Situ from Invasive Breast Carcinoma. J Mol Biomark Diagn 8: 342. doi: 10.4172/2155-9929.1000342 Copyright: © 2017 Abdallah DM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Comparative Immunohistochemical Study of P63, SMA, CD10 and Calponin in Distinguishing In Situ from Invasive Breast Carcinoma Dina M Abdallah*, and Nevine MF El Deeb Department of Pathology, Alexandria Faculty of Medicine, Egypt Abstract Background: Loss of the outer myoepithelial layer is the hallmark of invasive carcinoma, and demonstration of this loss can be documented by immunohistochemical techniques. The purpose of this study was to compare the specifcity and sensitivity of four of the most commonly used- markers of myoepithelial cells: P63, SMA, CD10 and Calponin in distinguishing in situ from invasive breast carcinoma. Material and methods: Immunostaining using antibodies against P63, SMA, CD10 and Calponin was performed on representative paraffn sections from 40 cases of breast masses examined at the Department of Pathology, Alexandria Faculty of Medicine, and diagnosed as ductal carcinoma in situ ± an invasive ductal or lobular carcinoma. Results: Calponin yielded a slightly higher sensitivity than each of P63, CD10 and SMA (65% vs 54%, 19% and 17%, respectively). The results of both semiquantitative assessment and computerized image analysis of immunohistochemically-stained sections were statistically correlated, statistically p63 showed the highest specifcity for myoepithelium and the least expression in non-myoepithelial layer of all antibodies tested. In contrast, SMA showed the least specifcity and highest non-myoepithelial expression especially in stromal myofbroblasts and in vascular smooth muscle cells. Conclusions: Calponin and P63 are more sensitive myoepithelial markers as compared to CD10 and SMA; with Calponin slightly more sensitive than P63. SMA should not be used alone as a myoepithelial marker due to its low specifcity. Keywords: Breast carcinoma; Myoepithelial cells; Cytokeratins; Mammary glands Introduction Myoepithelial cells (MEC) are contractile elements found in salivary, sweat, and mammary glands that show a combined smooth muscle and epithelial phenotype [1]. Normal breast glands and ducts are composed of 3 cell types that express diferent subsets of proteins: luminal, basal, and myoepithelial [1,2]. Te luminal and basal cell types express diferent cytokeratins (CKs); myoepithelial cells (MECs) express basal cell-type CKs and other more specifc markers, such as smooth muscle actin, calponin, and p63. An intact MEC layer is seen in both benign and in situ lesions, whereas loss of the MEC layer is considered the gold standard for the diagnosis of invasive cancer [2]. Carcinoma in situ (CIS) is defned as a proliferation of malignant epithelial cells confned by the basal lamina, whereas invasive carcinoma penetrates and grows beyond the basement membrane of the microanatomic structure in which it arises. Invasive ductal carcinoma, even the smallest, is treated diferently from ductal carcinoma in situ (DCIS). Ruling out foci of invasion is most problematic in cases of extensive high-grade DCIS accompanied by prominent periductal stromal fbrosis and infammation. Another diagnostic problem in which immunohistochemistry (IHC) can be of help is distinguishing ductal/lobular CIS- involving sclerosing adenosis or other complex sclerosing lesions from invasive carcinoma [3]. Earlier investigators approaching this problem stained for basal lamina components but found this could not reliably distinguish in situ from invasive tumors because some invasive carcinomas produce basement membrane components including laminin type IV collagen and type VII collagen [4]. Because MEC are not always readily identifable on routine haematoxylin and eosin stained sections, many immunohistochemical methods have been used to highlight an intact MEC layer. Given the mixed epithelial and smooth muscle phenotype of MEC, and the need to distinguish the MEC layer from the epithelial cell layer, most of the markers used are directed against smooth muscle related antigens. Except in the rare cases of myoepithelial carcinoma usual ductal carcinoma cells are negative for MEC markers [3]. SMA is a sensitive marker of myoepithelial diferentiation, but it is not specifc, because any cell with substantial expression of actin is positive for SMA. In the breast, myofbroblasts and blood vessels are generally positive for SMA. Tis becomes problematic in lesions where there are either myofbroblasts or blood vessels in close proximity to the epithelial lesion in question. CD10, the common acute lymphoblastic leukaemia antigen, was originally described as a leukaemia associated antigen expressed in lymphoid precursors and germinal B cells [5,6]. Te expression of this marker has been demonstrated in a wide range of non-haemopoietic tissues, including glomerular cells of the kidney, epithelial cells of the prostate gland and small and large intestine, endometrial stromal cells, [7] and MEC of the breast [7-9]. Te nuclear stain, p63, a member of the p53 gene family, shows no cross-reactivity with myofbroblasts or vascular smooth muscle.