Metachronous Double Primary Malignancies of Invasive Ductal Carcinoma of the Breast and Primary Ovarian Angiosarcoma.

Background & Objective: Primary ovarian angiosarcoma (POA) is an exceptionally rare and aggressive endothelial malignancy, accounting for less than 1% of all ovarian cancers. Its diagnosis is often challenging due to nonspecific clinical features and histologic overlap with other ovarian tumors. Case Presentation: A 47-year-old woman presented with progressive abdominal distension, intermittent vaginal bleeding, and constipation, four months after completing chemoradiotherapy for invasive ductal carcinoma of the breast. Imaging revealed a 14.6 cm solid-cystic pelvic mass, and histopathological examination demonstrated CD31 and ERG positivity, confirming a rare diagnosis of primary ovarian angiosarcoma. BRCA2 immunohistochemistry was negative. Conclusion: The metachronous occurrence of triple-negative invasive ductal carcinoma and primary ovarian angiosarcoma represents an extremely rare clinical scenario. Although angiosarcomas have occasionally been reported in individuals with BRCA mutations, the relationship between BRCA alterations and ovarian angiosarcoma remains unclear. In the present case, immunohistochemical analysis demonstrated negative BRCA2 expression. Further molecular characterization of ovarian angiosarcomas is needed to better understand their biology and potential relationship with hereditary cancer syndromes.