Malignant Mesenchymal Tumor of the Breast: Primary Chondrosarcoma

SUMMARY: BACKGROUND: Primary mesenchymal tumors are an extremely rare malignancy of the breast. CASE REPORT: A 52-year-old woman presented with a rapidly growing breast mass. Physical examination established a large and round mass with regular margins in the upper-outer quadrant of the right breast. Ultrasound showed a hypoechoic solid mass (41 × 36 mm) with lobulated contours. Mammography revealed a hyperdense and relatively regular-shaped mass giving the impression of a benign tumor. However, a pathologic report of atypical cells after fine needle aspiration necessitated surgical excision. The mass was removed with a wide local excision. The tumor was diagnosed as a high-grade chondrosarcoma of the breast by histopathological analysis. Following the final diagnosis, we performed a modified radical mastectomy based on the knowledge that this malignancy is generally refractory to radiotherapy. The regional lymph nodes and local adjacent tissues were free of metastasis. The tumor was negative for estrogen and progesterone receptors as well as HER2. CONCLUSION: Chondrosarcoma tends to grow rapidly. Physical examination usually reveals a large, round mass. The tumor is regular-shaped, round, and complex echoic on Mammography and ultrasound. It usually does not invade regional structures. Surgery remains the only effective treatment.