Metaplastic Breast Carcinoma With Chondroid Differentiation: A Rare Variant of Infiltrative Carcinoma in a 38-year-old Woman

BMJ Case Rep. 2017 Jun 15;2017:bcr2016217687. doi: 10.1136/bcr-2016-217687.


Metaplastic breast carcinoma (MBC) is a rare type of invasive breast carcinoma, and chondroid differentiation is even rarer. Here we report a case of MBC with extensive chondroid differentiation in a 38-year-old woman who presented with a lump in her left breast. Ultrasound findings were most compatible with those of giant fibroadenoma. A histopathological examination revealed a malignant lesion comprising neoplastic epithelial cells arranged in solid nests, with large areas of chondroid differentiation. Neoplastic chondroid cells exhibited a positive reaction for S-100, patchy positive reaction for pan-cytokeratin (AE1/AE3) and negative reaction for epithelial membrane antigen. Both carcinomatous and chondroid cells exhibited p53 overexpression. Sentinel lymph node biopsy revealed no tumorous involvement.

Keywords: breast cancer; pathology.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Breast Neoplasms / diagnostic imaging
  • Breast Neoplasms / pathology*
  • Breast Neoplasms / radiotherapy
  • Breast Neoplasms / surgery
  • Carcinoma / diagnostic imaging
  • Carcinoma / pathology*
  • Carcinoma / surgery
  • Cell Differentiation*
  • Diagnosis, Differential
  • Female
  • Fibroadenoma / diagnostic imaging
  • Humans
  • Keratins / metabolism
  • Metaplasia / pathology*
  • Neoplasm Invasiveness / pathology*
  • Treatment Outcome
  • Tumor Suppressor Protein p53 / metabolism
  • Ultrasonography, Mammary


  • Tumor Suppressor Protein p53
  • Keratins