Multiple Thrombi mimicking metastases in the right atrium of patients with non-Hodgkin's lymphoma diagnosed by multimodal cardiac imaging：one case report

Abstract

Background： Right-side heart mass can be found incidentally on routine transthoracic echocardiography (TTE). Accurate diagnosis of cardiac mass often requires more than one imaging method. We present a mid-age woman with non-Hodgkin lymphoma who was found to have multiple right atrial masses mimicking metastases on routine TTE, which were diagnosed as thrombi by multimodal cardiac imaging eventually. The masses were removed by cardiopulmonary bypass thoracotomy because of a high risk of pulmonary embolism. Case presentation: A 52-year-old woman was diagnosed with primary mediastinal diffuse large B cell lymphoma (DLBCL) almost six months prior. The TTE revealed multiple masses in the right atrium with normal cardiac function when she was being evaluated for the next chemotherapy. On arrival, she was hemodynamically stable and asymptomatic. Physical examination was no remarkable. Laboratory findings showed leukocytosis of 17,900 cells/mm3, hemoglobin of 7.5 mg/dL, and a normal D-dimer level. The suspicious diagnosis of right atrial metastasis was made by TEE. However, the diagnosis of right atrial thrombi was made by contrast CMR. Finally, the 18F-FDG PET-CT demonstrated no metabolic activity in the right atrium, which further established the diagnosis of thrombi. Eventually, the masses were removed by cardiopulmonary bypass thoracotomy because of a high risk of pulmonary embolism, and confirmed thrombi by histopathology. Conclusions: This case highlights the importance of multimodality cardiac imaging in the appropriate diagnosis of a RA masses in patient of lymphoma. Diagnosis of RA masses can be made using multimodal cardiac imaging like TTE, TEE and CMR, even PET. Echocardiography is the most commonly used on multimodal imaging in cardiac thrombus. CMR has high specificity in differentiating a tumor from thrombus, and 18F-FDG PET has more sensitivity to determine the nature of the masses.