Matrix-producing Carcinoma of the Breast Successfully Treated with Neoadjuvant Chemotherapy—A Case Report—

Abstract

Matrix-producing carcinoma of the breast is a relatively rare histological type of breast cancer and accounts for approximately 0.1% of all breast carcinomas. Most matrix-producing carcinomas are triple-negative breast cancers, which often recur within two-and-a-half years postoperatively. Reportedly, the 5-year survival rate of this malignancy is poorer than that of other types of breast cancer. Few reports in Japan have described neoadjuvant chemotherapy in these cases. We report a case of successful neoadjuvant chemotherapy in a patient with matrix producing carcinoma. A 45-year-old woman developed a right breast mass for which she did not initially seek care. However, the mass gradually increased in size and became painful ; therefore, she visited our department for further evaluation. A 13 cm mass was detected in the CC area of her right breast, and she was diagnosed with a matrix-producing carcinoma based on histopathological evaluation of needle biopsy specimens. Positron emission tomography-computed tomography revealed tracer uptake in a right axillary lymph node without distant metastasis. The tumor shrank following six cycles of fluorouracil, epirubicin, and cyclophosphamide therapy and 12 cycles of paclitaxel as neoadjuvant chemotherapy, and right partial mastectomy and axillary lymphadenectomy were considered feasible in this case. The patient received post-adjuvant radiotherapy to the conserved breast and is currently being followed-up.