28563 – RADIOINDUCED BREAST ANGIOSARCOMA: A CASE REPORT

Abstract

Introduction: Angiosarcomas are malignant tumors composed of neoplastic endothelial cells of blood or lymphatic vessels. They can develop in the skin, lungs, liver, or spleen, but 8% of these tumors occur in the breasts. They are classified into
primary and secondary types. Primary angiosarcomas are rare tumors, with an incidence ranging from 0.04% to 0.05% of
malignant breast tumors. Secondary angiosarcomas are associated with post-mastectomy lymphedema (Stewart-Treves
syndrome) and those linked to post-surgical radiotherapy, whether after radical or conservative breast surgery, with an
incidence ranging from 0.14% to 0.3% (radiation-induced tumors). Methodology: To write this case report, the authors
conducted a literature review across the following databases: the United States National Library of Medicine (PubMed),
Latin American and Caribbean Literature in Health Sciences (LILACS), Virtual Health Library (VHL), the National Institute
for Health and Care Excellence (NICE), Cochrane Library, and Scientific Electronic Library Online (SciELO). A total of 45
publications related to the topic were identified, from which 12 articles were selected. Subsequently, all selected studies
were read in full, applying eligibility criteria to determine inclusion or exclusion. Inclusion criteria: only original articles,
clinical trials, and case reports written in the last five years in English, Spanish, and Portuguese that involve: (i) angiosarcoma of the breast as the disease, and (ii) radiation induction. Exclusion criteria: (i) editorials/expert opinions, (ii) letters/communications, and (iii) publications in languages other than those specified for the study. Conclusion: Following
an incisional biopsy, the histopathological analysis revealed an atypical vascular lesion. Immunohistochemistry showed
positivity for CD31 and CD34 antigens, absence of estrogen receptors, and amplification of the C-MYC oncogene confirmed the diagnosis of radiation-induced angiosarcoma, with a grade III anaplasia. Mammography demonstrated only skin
thickening in the upper quadrants of the right breast (Breast Imaging Reporting and Data System — BI-RADS 2), while
breast ultrasonography revealed well-defined subcutaneous nodular formations, parallel to the skin, with parietal calcifications suggestive of fat necrosis (BI-RADS 3). Subsequently, the patient underwent a modified radical mastectomy
according to Madden’s technique, along with evaluation of the lateral thoracic sentinel lymph node and the para sentinel
lymph node, both of which were negative for malignancy. The patient showed an excellent postoperative course and, six
months later, remains in good health, asymptomatic, with no evidence of active disease.