Immunophenotyping analysis in invasive micropapillary carcinoma of the breast: role of CD24 and CD44 isoforms expression

Breast. 2012 Apr;21(2):165-70. doi: 10.1016/j.breast.2011.09.004. Epub 2011 Oct 20.


We analyzed immunohistochemically the expression of CD24 and spliced variants of CD44v5 and v9 in invasive micropapillary carcinoma (IMPC) of the breast that is a rather aggressive tumor characterized by alteration of cells adhesion molecules, early lymph node metastases and poor prognosis. We analyzed 31 high-grade IMPCs and compared their expression to 22 high grade (G3) invasive ductal carcinomas of the breast (IDCs). We found a higher expression of CD24 in high-grade IMPCs with a peculiar inverted apical localization, compared to IDCs, showing a strong cytoplasmic staining; normal breast tissue resulted completely negative. IMPCs showed reduced expression of CD44v5 and CD44v9 compared with IDCs, but without a statistical significant difference. This study demonstrated that IMPC represents a distinct entity of breast carcinoma with high expression of CD24 with a typical inverted apical membrane pattern and reduction of CD44 isoforms v5 and v9, compared to IDCs. These features could explain the high lymph-vascular invasion propensity and higher metastatic capability of these tumors and could be a useful tool for a future targeted therapy.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / analysis
  • Biomarkers, Tumor / metabolism*
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • CD24 Antigen / analysis
  • CD24 Antigen / metabolism*
  • Carcinoma, Papillary / metabolism*
  • Carcinoma, Papillary / pathology
  • Female
  • Humans
  • Hyaluronan Receptors / analysis
  • Hyaluronan Receptors / metabolism*
  • Immunophenotyping
  • Lymphatic Metastasis
  • Middle Aged
  • Neoplasm Invasiveness
  • Protein Isoforms / analysis
  • Protein Isoforms / metabolism


  • Biomarkers, Tumor
  • CD24 Antigen
  • CD24 protein, human
  • CD44 protein, human
  • Hyaluronan Receptors
  • Protein Isoforms