A Multi-Modality Approach to the Assessment of a Right Atrium Mass in a Female Patient with Breast Cancer Undergoing Neoadjuvant Chemotherapy.

Echocardiography remains a vital part of the initial assessment and monitoring of oncological patients. It allows for proper treatment selection but can also reveal life-threatening complications, including impaired left ventricular function or thromboembolism. It can rarely detect intracardiac masses that require further investigation. In the presented case, a 51-year-old female patient with left-sided breast cancer, who had undergone neoadjuvant chemotherapy, was hospitalised due to a right atrial mass identified via routine transthoracic echocardiography (TTE). Initial anticoagulation therapy showed no clinical improvement. Follow-up TTE revealed a 12 × 19 mm hyperechogenic, mobile mass in the right atrium (RA). Computed tomography angiography (CTA) ruled out pulmonary embolism and revealed that the mass was located close to the tip of the vascular access port. Transoesophageal echocardiography showed that the lesion was not connected to the vascular port. Based on location and mobility, the lesion was most consistent with a cardiac myxoma. After the Heart Team made a decision, endovascular intervention using a vacuum-assisted device was performed without complications. Histopathological examination excluded thrombosis and myxoma, revealing a fibro-inflammatory lesion. A multimodality approach is necessary to assess RA masses. However, even an extensive evaluation could be misleading, so treatment options should always be subject to the Heart Team's decision.