Myoepithelial cell staining patterns of papillary breast lesions: from intraductal papillomas to invasive papillary carcinomas

Am J Clin Pathol. 2005 Jan;123(1):36-44. doi: 10.1309/xg7tpq16dmjav8p1.

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."

MeSH terms

  • Breast / pathology*
  • Breast Neoplasms / chemistry
  • Breast Neoplasms / pathology*
  • Calcium-Binding Proteins / analysis
  • Calponins
  • Carcinoma, Papillary / chemistry
  • Carcinoma, Papillary / pathology*
  • DNA-Binding Proteins
  • Epithelial Cells / chemistry
  • Female
  • Genes, Tumor Suppressor
  • Humans
  • Immunohistochemistry
  • Microfilament Proteins
  • Myosin Heavy Chains / analysis
  • Papilloma, Intraductal / chemistry
  • Papilloma, Intraductal / pathology*
  • Phosphoproteins / analysis
  • Staining and Labeling
  • Trans-Activators / analysis
  • Transcription Factors
  • Tumor Suppressor Proteins

Substances

  • Calcium-Binding Proteins
  • DNA-Binding Proteins
  • Microfilament Proteins
  • Phosphoproteins
  • TP63 protein, human
  • Trans-Activators
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Myosin Heavy Chains