Metaplastic breast cancer with chondrosarcomatous differentiation combined with concurrent bilateral breast cancer: A case report

Abstract

Background: Metaplastic breast carcinoma (MBC) is a rare subtype of invasive breast cancer comprising malignant epithelial and mesenchymal cells. Compared with other invasive breast cancers, MBC is not only histologically distinctly heterogeneous but also has a rapid and aggressive growth pattern, which leads to a significant risk of recurrence and mortality.

Case summary: In this study, we report the case of a patient with a large left breast mass diagnosed with bilateral invasive ductal carcinoma in both breasts after a preoperative core needle aspiration biopsy of the bilateral breast mass. The patient received neoadjuvant chemotherapy and underwent bilateral breast modified radical mastectomy. Postoperative pathology suggested carcinosarcoma with predominantly chondrosarcoma in the left breast and invasive ductal carcinoma (luminal B) in the right breast. As the patient did not achieve complete pathological remission after six cycles of neoadjuvant chemotherapy, we administered six months of intensive capecitabine treatment. Then the patient was switched to continuous treatment with endocrine therapy using letrozole + goserelin, and the patient is currently in stable condition. However, as MBC of the breast is concurrently diagnosed with chondrosarcoma differentiation, our case is sporadic.

Conclusion: Given the variety of immunohistochemical types of bilateral breast cancer, achieving effective chemotherapy should be a key research focus.

Keywords: Bilateral breast cancer; Carcinosarcoma; Case report; Chondrosarcoma differentiation; Invasive ductal carcinoma; Metaplastic breast cancer.

Figure 1

There is a huge mass in the left breast, with local skin cyanosis and varicose veins.

Figure 2

A huge cystic solid mixACed mass. Computed tomography contrast enhancement of the breast.

Figure 3

Core needle biopsy of both breast masses. A: Fine needle aspiration cytology to identify tumor cells (4 × 10); B: An immunohistochemical pathological section of invasive ductal carcinoma in the left breast (4 × 4); C: An immunohistochemical pathological section of invasive ductal carcinoma in the right breast (4 × 10).

Figure 4

After six cycles of neoadjuvant chemotherapy, the tumor shrank significantly. Nuclear magnetic resonance imaging contrast enhancement of the breast.

Figure 5

Immunohistochemical picture of left breast chondrosarcoma component after operation. A: Carcinosarcoma can be found in the invasive ductal carcinoma of the left breast, and the carcinosarcoma is differentiated into chondrosarcoma (4 × 4); B: Vimentin (+) expression was positive (4 × 4).