Myxofibrosarcoma of the Breast: Case Report

Abstract

INTRODUCTION: Sarcomas of the breast account for less than 1% of all breast cancers. All of them share some clinical and pathological features. Myxofibrosarcoma is characterized by nodular growth, a mixoid matrix, a course, plexiform capillary pattern, and spindle or stellate tumor cells with hyperchromatic, atypical nuclei. Pathologic diagnosis is based on the overall morphology of the tumor and the exclusion of metaplastic carcinoma. This case report describes a mixofibrosarcoma of the breast in a young woman. CASE REPORT: A 26 year-old woman with two separate lumps in the left breast for the past three years. On clinical examination, there were two firm tumors measuring 5cm and 6 cm in the upper inner quadrant. There was no palpable ipsilateral axillary limph nodes. Ultrassonography showed low echogenic masses, a nonhomogeneous internal echo pattern, 4, 1 x 3, 9 cm and 3, 1 x 2, 3 cm in size. Core biopsy was performed twice and showed a myxoid lipomatous tumor. We performed a local excision which revealed a mesenchymal malignant tumor with myxoid and pleomorphic components. The immunohistochemestry (IHC) was negative for cytokeratin and S 100. The patient was submitted to simple mastectomy and the histopathological analyses confirmed the diagnosis of myxofibrosarcoma of the breast. DISCUSSION: Sarcomas of the breast are a heterogeneous group of tumors. The morphologic and clinical spectrum of each specific subtype of mammary sarcoma has been slow to emerge. IHC is a widely available diagnostic method in cases in which the morphology is ambiguous. Pathologic diagnosis of mammary myxofibrosarcoma is based on the overall morphology of the tumor and the exclusion of metaplastic carcinoma. There are no IHC markers for myxofibrosarcoma.