Discussion
Diagnosis
Radiation-Associated Angiosarcoma
Discussion
Angiosarcoma is a tumor composed of malignant vascular endothelial cells that generally stain strongly positive with vascular markers such as ERG, CD34, CD31 and factor VIII. Although radiation-associated angiosarcoma is a rare malignancy, occurring in less than 0.3 percent of women treated with radiation therapy for breast cancer, it is the most common type of secondary angiosarcoma. The incidence peaks 5-10 years after treatment, but remains elevated for up to 30 years. Patients typically present with dark red to purple skin discoloration that is macular to nodular and is often mistaken for a hematoma. The average size is 5 cm and the majority of lesions are greater than 2 cm. MYC amplification, detected by immunohistochemistry, has a sensitivity of approximately 80% and specificity of 100 percent in radiation associated angiosarcoma.
Given the patient history, recurrent breast IDC is in the differential. A morphological comparison of her prior breast carcinoma resection specimen (Figure 7) and negative staining for pan-cytokeratin and GATA3, rule out the diagnosis of recurrent breast IDC. An atypical vascular lesion, which may also present after therapeutic radiation exposure, is also in the differential. However, these lesions typically have bland nuclei lining the vessels, do not involve the subcutaneous tissue, and lack MYC amplification.
The treatment of radiation-associated angiosarcoma is surgical removal with wide margins, with many patients requiring a mastectomy. Chemotherapy and radiation therapy have uncertain benefit. The median recurrence free survival is three years with an overall survival of less than six years.
References
Baker GM, Schnitt SJ. Vascular lesions of the breast. Semin Diagn Pathol. 2017;34(5):410-419.
Cornejo KM, Deng A, Wu H, et al. The utility of MYC and FLT4 in the diagnosis and treatment of postradiation atypical vascular lesion and angiosarcoma of the breast. Hum Pathol. 2015;46(6):868-875.
Sheth GR, Cranmer LD, Smith BD, Grasso-Lebeau L, Lang JE. Radiation-induced sarcoma of the breast: a systematic review. Oncologist. 2012;17(3):405-418.