Case 20180315 4x 1Case 20180315 20x 1Case 20180315 20x 2
The patient is a 60 year old female with left breast mass, who underwent needle localized lumpectomy.

 What is the most likely diagnosis?

A. Invasive ductal carcinoma.
Matrix-producing carcinoma.
Metaplastic carcinoma with squamous elements.
E. Phyllodes tumor


The answer is “B”, Matrix-producing carcinoma


The sections show infiltrating ductal carcinoma components admixed with mesenchymal components showing chondroid differentiation. Historically, the term “matrix-producing carcinomas” was applied to a subgroup of metaplastic carcinomas with mesenchymal elements where an abrupt transition from epithelial to the mesenchymal components without the presence of intervening spindle cells was found. It should be noted that although in the vast majority of cases areas of epithelial differentiation can be readily found, in some cases, extensive sampling is required for the carcinomatous areas to be documented. Immunohistochemical analysis reveals the expression of epithelial markers, usually high molecular weight keratins.


Lakhani SR et al. WHO Classification of Tumors of Breast, 4th edition

Contributed by Shuko Harada, M.D.