Radiation induced malignant histiocytoma of the contralateral breast following treatment of breast cancer: a case report and review of the literature

Radiation therapy (XRT) is an important modality for treatment of breast cancer. Its use has occasionally resulted in the development of secondary malignancies. We describe this interesting case of a 46-year-old woman who developed malignant fibrous histiocytoma in the contralateral breast 6 years after a lumpectomy followed by radiation therapy for infiltrating ductal carcinoma. The role of XRT in the treatment of breast carcinoma and development of Radiation induced Sarcoma (RIS) is examined. RIS has a current incidence of 0.03% to 0.2% in patients undergoing XRT for breast carcinoma. The role of XRT in the development of RIS has been clearly demonstrated. Clinical presentations vary, and diagnosis is commonly delayed. Treatment consists of wide surgical excision. Development of RIS has an average latency of over 10 years and correlates with the dose and technique of XRT. Breast conserving surgery followed by irradiation is becoming increasingly popular leading to an increasing number of sarcomas. Because of post-irradiation changes, detection of a new lesion is difficult, resulting in delayed diagnosis and poor prognosis in these patients. However, the benefit of XRT far outweighs the risk of RIS and should not affect the decision to treat these patients with this modality.