Metaplastic carcinoma of the breast with chondroid differentiation (matrix-producing carcinoma): study of the diagnostic cost-effectiveness of fine-needle aspiration biopsy and needle core biopsy.

UNLABELLED: Metaplastic carcinoma with chondroid differentiation (MMPC) is a subtype of breast metaplastic carcinoma with mesenchymal differentiation. Although fine-needle aspiration (FNAB) and core-needle biopsy (CNB) are commonly used for the diagnosis of breast cancer, not enough studies proving the diagnostic cost-effectiveness of these techniques for the identification of MMPC have been published so far. The aim of this study was to investigate the concordance between the presurgical diagnosis using FNAB/CNB and the definitive diagnosis in the surgical specimen in pure MMPC. A case of MMPC is also reported.

STUDY DESIGN: All cases of MMPC diagnosed in our institution from 1995 to 2011 were reviewed. The presence of chondroid differentiation in cytological studies or biopsies and the proportion of chondroid matrix in the surgical specimen were evaluated.

RESULTS: A total of 13 cases of pure MMPC were collected. The diagnosis was suspected in 25% of FNABs and was rendered in 40% of CNBs.

CONCLUSIONS: The chondroid component in MMPC is hard to identify by FNAB and CNB. The random distribution and proportion of the chondroid differentiation in the tumour and the expertise in performing the technique and in identifying the chondroid component may play an important role in the diagnosis of MMPC using these techniques.