title: Myoepithelial cell staining patterns of papillary breast lesions: from intraductal papillomas to invasive papillary carcinomas.
abstract: We evaluated 25 intraductal papillomas and 18 papillary carcinomas (invasive, 4; micropapillary ductal carcinoma in situ [DCIS], 5; cases originally classified as intracystic/intraductal papillary carcinoma, 9) by calponin, smooth muscle myosin heavy chain (SMM-HC), and p63 immunostains. Calponin, SMM-HC, and p63 labeled myoepithelial cells (MECs) in all intraductal papillomas and all micropapillary DCIS cases. The invasive papillary carcinoma cases were uniformly negative for all stains. The 9 cases originally diagnosed as intracystic/intraductal papillary carcinoma showed more variable results, with identification of an MEC layer in only 4 cases. Comparison of staining of MECs by these 3 stains showed that calponin was more sensitive and intense than SMM-HC; however, there was cross-reactivity with myofibroblastic cells. Staining with p63 was discontinuous, making interpretation of an intact myoepithelial layer difficult. Of 9 cases originally classified as intraductal papillary carcinoma, 5 showed absence of a basal MEC layer by immunohistochemical analysis. The lack of a basal MEC layer in these cases suggests a spectrum of progression from in situ to invasive disease and might help explain distant metastases from previously reported "intraductal papillary carcinoma."
authors.affiliation: Department of Pathology, University of Texas Health Science Center at San Antonio, 78229-3900, USA.
authors.forename: Cheryl B
authors.initials: CB
authors.lastname: Hill
authors.forename: I-Tien
authors.initials: IT
authors.lastname: Yeh
mesh_terms: D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology*; D002135:Calcium-Binding Proteins / Q000032:analysis; D002291:Carcinoma, Papillary / Q000737:chemistry / Q000473:pathology*; D004268:DNA-Binding Proteins; D004847:Epithelial Cells / Q000737:chemistry; D005260:Female; D016147:Genes, Tumor Suppressor; D006801:Humans; D007150:Immunohistochemistry; D008840:Microfilament Proteins; D018995:Myosin Heavy Chains / Q000032:analysis; D018300:Papilloma, Intraductal / Q000737:chemistry / Q000473:pathology*; D010750:Phosphoproteins / Q000032:analysis; D013194:Staining and Labeling; D015534:Trans-Activators / Q000032:analysis; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D000096985:Calponins
chemical_list: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D008840:Microfilament Proteins; D018995:Myosin Heavy Chains; D010750:Phosphoproteins; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D000096985:Calponins; C115051:TP63 protein, human