Sarcoma pleomórfico de mama radioinduzido pós-tratamento conservador de câncer de mama inicial ­ relato de caso / Radiation-Induced Undifferentiated Pleomorphic Sarcoma after Breast Conservative Therapy: A Case Report

ABSTRACT

Introduction: Breast sarcoma is a rare form of malignancy that arises from connective tissue, comprising less than 5% of all sarcomas. Undifferentiated pleomorphic sarcoma (UPS) of the breast is a rare and aggressive subtype of radiation-induced sarcoma that can arise in treated breast cancer patients. The diagnosis is challenging and often missed due to the low incidence, long latency period, unspecific imaging finding, and difficulties in clinical and histological detection. Case report A 56-year-old woman was diagnosed with early-stage triple-negative breast cancer in 2013 and underwent breast-conserving therapy (BCT). After 5 years follow-up, she developed mastalgia and breast induration, and behind mammography and ultrasound without suspicious lesions, a Magnetic Resonance Imaging (MRI) was performed and showed a highly suggestive of malignancy mass measuring 8.0cm and invading chest wall. The core biopsy revealed a spindle cells malignant tumor, negative for pan cytokeratine and most of immuno-histochemical (IH) markers, suggesting sarcoma, but requiring study of surgical specimen to exclude Metaplastic Carcinoma. She underwent Halsted Radical Mastectomy, full-thickness left anterior chest wall resection contemplating segments of the 4th and 5th ribs and reconstruction with synthetic mesh. The surgical specimen evidenced a UPS, with clear margins. The patient had good postoperative recovery, and remains the follow up with the Mastology team.