A 75-year-old man was referred urgently to a cardiology department because of New York Heart Association (NYHA) class IV symptoms. The patient reported 1-week long exacerbation of dyspnea, which initially occurred during mild exertion and finally at rest. Medical history included arterial hypertension, thrombocytopenia, and anemia. Physical examination revealed tachypnea and edema of lower limbs up to the knees. Blood pressure was 150/90 mm Hg. Electrocardiogram showed atrial flutter with heart rate of 70 bpm. Laboratory tests showed mild anemia (hemoglobin 10.1 g/dl; reference range [RR], 12–17 g/dl), elevated level of N-terminal pro–B-type natriuretic peptide (5610 pg/ml; RR <⁠134 pg/ml), and high-sensitive troponin T (96.9 ng/l; RR <⁠14 ng/l), elevated level of C-reactive protein (29.6 mg/l; RR <⁠5 mg/l), and renal failure with reduced glomerular filtration rate (29 ml/min/1.73 m2; RR >60 ml/min/1.73 m2). Transthoracic echocardiography (TTE) revealed preserved left ventricular ejection fraction (60%) and a mass in the right atrium, approximately 7 cm × 3 cm in size, protruding into the right ventricle (Figure 1A). Urgent transesophageal echocardiography (TEE) showed a heterogeneous, vascularized mass in the right atrium, which infiltrated the atrial septum, the left atrium, and the aortic annulus (Figure 1B–1E). We performed computed tomography (CT) with electrocardiographic gating. The scan confirmed a mass in the right atrium and additionally revealed an enlarged lymph node (3 cm × 2 cm) in the mediastinum. Whole body CT scan was then performed for disease staging and exclusion of other tumor with potential metastases to the heart. Additionally, chest CT showed pulmonary embolism with embolic material in the right pulmonary artery.

Figure 1. Echocardiography images of a tumor in the right atrium. The mass is indicated with white arrows. A – initial transthoracic examination; B–E – transesophageal examinations (C – impaired blood flow between the tumor and the structures of the right heart); F – transthoracic examination after 2 cycles of chemotherapy showing a great reduction in the tumor size

Abbreviations: MV, mitral valve

Due to the location in the right atrium, invasive nature of the tumor, and no signs of other neoplastic diseases visible on the CT scan, initial diagnosis was a primary heart tumor, probably angiosarcoma with metastases to the lymph nodes.1 The heart team consulted the patient, yet due to the infiltration of the aortic annulus, the ascending aorta, and the left atrium, disqualified him from surgical treatment.

In the next step, we performed myocardial biopsy via the right femoral vein access. A biopsy of the mass localized in the right atrium could be challenging, and in order to reduce the risk of complications we performed it with TEE guidance2 (Supplementary material, Figure S1). The histopathologic examination confirmed diffuse large B-cell lymphoma (DLBCL). The final stage of the disease was IIa in the Ann Arbor classification. After obtaining the biopsy result, we abandoned the previously considered angiography with intracoronary injection of echocardiographic contrast and potential further embolization of the tumor, and instead qualified the patient for chemotherapy. After 2 weeks from the initial hospital admission the patient started R-CHOP immunochemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone).

Apart from the antineoplastic agents, the patient was treated with torasemide 20 mg daily, furosemide 40 mg daily, and lercanidipine 10 mg daily. Due to the neoplastic process and pulmonary embolism the patient received anticoagulation with a low-molecular-weight heparin (1 mg/kg body weight twice a day).

After 3 months, the patient completed 2 courses of chemotherapy. He was in NYHA class II and did not have any episodes of heart failure exacerbation. We performed TTE, which showed a significant reduction in the tumor size (3.5 cm × 2.5 cm) (Figure 1F) and an increase in the left ventricular stroke volume.

Primary heart tumors are much rarer than secondary tumors and majority of them are benign. Primary malignant heart tumors are in minority and lymphomas are very rare neoplasms (1% of primary heart tumors)1,3 (additional data are displayed in Supplementary material, Table S1).

The presented case demonstrates a rare manifestation of DLBCL and shows a fundamental role of imaging modalities in the assessment of patients with heart failure. TTE is a relatively fast and widely available examination, and it is indicated in every case of a new onset of heart failure or exacerbation in previously stable patients.4 Due to its accessibility, TTE is also the first-choice examination for cardiac masses.5 Sensitivity of TTE in the detection of heart tumors is very high (>90%), yet differentiation of cardiac masses is challenging, and specificity of a correct diagnosis is below 70%. On the contrary, TEE offers better performance in differentiation of cardiac tumors (possibly >90%).5 However, as illustrated in this report, diagnostics of cardiac masses could be challenging, and histologic examination provides final diagnosis.

A mass in the cardiac cavities is a rare cause of heart failure. In this scenario, the mass impaired the right ventricular inflow and decreased the right ventricular stroke volume. Left ventricle failure was secondary to the right site abnormality and reduced preload. This case report also shows a great role of accuracy of the initial assessment. Not all TTE projections showed the mass, despite its large size.