Breast Cancer–Associated Thrombotic Microangiopathy: The Paradox of Stable Scans and Unstable Blood

Cancer-associated thrombotic microangiopathy (TMA) is a rare and often fatal consequence of solid and hematologic malignancies. We report a 69-year-old woman with metastatic hormone receptor–positive, human epidermal growth factor receptor 2–negative breast cancer who developed severe anemia without bleeding. Laboratory tests revealed erythrocyte destruction, low platelet counts, and the presence of schistocytes. Imaging suggested a stable tumor burden. A bone marrow biopsy confirmed cancer-associated TMA. This case shows that stable imaging does not rule out cancer progression or TMA. Early diagnosis of cancer-associated TMA is essential for timely therapy, improving survival rates, and quality of life.