Two cases of post-radiation sarcoma after breast cancer treatment.

We describe two cases of post-radiation sarcoma after breast cancer treatment. The first patient was a 61-year-old woman who underwent partial mastectomy of the right breast and adjuvant whole breast irradiation 7 years previously. Subsequently, a rapidly growing mass from the anterior arc of the right fifth rib was incidentally detected on an abdomino-pelvic computed tomography scan. The second patient was a 70-year-old woman who received neoadjuvant chemotherapy and a partial mastectomy of the left breast 9 years ago. Adjuvant irradiation was delivered to the whole breast and supraclavicular region. Subsequently, an approximate 8 cm mass developed in the left axillary area. Both patients received wide excision of the tumor with negative resection margins. The pathological diagnoses were osteosarcoma and undifferentiated pleomorphic sarcoma, respectively. Although post-radiation sarcomas are rare complications with a poor prognosis, enhanced awareness and early detection by clinicians are essential to improve outcomes via curative surgical resection.