From Dyspnea to Suspected Breast Cancer: A Post-traumatic Hematoma as a Diagnostic Pitfall.

Post-traumatic breast hematomas are uncommon but clinically relevant, as they may closely mimic breast cancer on both clinical examination and imaging. These hematomas may be large and persistent, particularly in patients receiving anticoagulant therapy. Conversely, breast cancer itself may present with hematoma formation, creating a diagnostic pitfall. With the increasing use of cross-sectional imaging for non-breast indications, incidental breast findings are detected with growing frequency. Although many of these findings are benign, their imaging appearance can occasionally mimic malignancy, often necessitating further diagnostic evaluation. We report the case of a 76-year-old woman who presented with progressive dyspnea, leading to a chest computed tomography (CT) for pulmonary evaluation. This examination revealed an incidental breast mass-like lesion. The patient reported a recent fall with subsequent ecchymosis of both breasts while on chronic anticoagulant therapy with apixaban. Clinical examination six months after the fall still demonstrated a large palpable mass measuring 60 x 50 mm with associated skin retraction in the right breast. The lesions in the left breast had resolved completely. Mammography, ultrasound, and magnetic resonance imaging (MRI) resulted in a Breast Imaging Reporting and Data System (BI-RADS) IV classification. The clinical examination in combination with the breast imaging was suggestive of locally advanced breast cancer. A core biopsy showed benign findings consistent with an organizing hematoma. It could, however, not rule out a malignant lesion. Following a multidisciplinary team meeting discussion, it was decided to repeat the clinical examination, imaging, and biopsy after two months. After two months, the deformation of the breast had increased, and the image was still BI-RADS IV, but the repeated core biopsy confirmed a complex organized hematoma without evidence of carcinoma. This case illustrates the diagnostic challenges associated with post-traumatic breast lesions. In this patient, clinical examination and imaging were unable to reliably distinguish an organized hematoma from breast cancer despite a clear history of trauma and anticoagulant therapy. Histological confirmation was therefore required. Persistent clinical-radiological discordance required a multidisciplinary approach. The decision to repeat the assessment after an appropriate follow-up was essential to ensure diagnostic safety and avoid both delayed cancer diagnosis and unnecessary overtreatment.