Right Atrial Mass in a Patient With T-Cell Chronic Lymphocytic Leukemia
An Unusual Mechanism of Thrombus Formation
A 71-year-old woman with refractory T-cell (CD4+) chronic lymphocytic leukemia who had been treated with chemotherapy and leukapheresis with poor control of leucocytosis was admitted because of fever, cough, and chest pain. A chest x-ray showed a right basal pneumonia, and the cytological examination of sputum showed Aspergillus fumigatus (Figure 1). The ECG at admission showed a first-degree atrioventricular block (Figure 2A). The patient was started on broad-spectrum antibiotics and liposomal amphotericin B. Shortly before admission, because of sinus tachycardia, an ECG with Holter monitoring was performed; it showed a run of supraventricular tachycardia (Figure 2B). Therefore, while in the hospital, the patient underwent cardiac evaluation. Two-dimensional echocardiography showed a round (20×16 mm) floating mass in the right atrium, close to the superior caval vein (Figure 3A, Movie). A thrombus near the distal tip of the central venous catheter was suspected, and the patient was started on nadroparin 6000 U injected subcutaneously twice daily. At the time of echocardiography, blood counts showed severe leucocytosis (white blood cell count, 396.100/μL; lymphocytes, 384.940/μL). After 2 weeks of therapy with low-molecular-weight heparin, the patient underwent transesophageal echocardiography, which did not show any reduction of the atrial mass and excluded any relation to the central venous catheter (Figure 3B). A cardiac computed tomography scan was performed, which showed an 8-mm defect in the right atrium with irregular shape and contrast enhancement (Figure 3C). The patient died of multiorgan failure 52 days after admission. At autopsy, a multiorgan extensive leukemic infiltration was detected. The atrial mass, located at the junction of the inferior caval vein with the atrium and attached to the crista dividens, measured 20×18×15 mm (figure 3D). Histologically, we found an infiltration of the atrial wall by clusters of cells that reached and disrupted the endocardial atrial surface, providing a likely cause for the stratified thrombotic apposition (Figure 4A through 4D). The clustered cells were CD45-positive (Figure 4C) and CD3-positive (Figure 4D) T-lymphocytes and were confined to the peduncle.
The online-only Data Supplement, which contains a movie, can be found at http://circ.ahajournals.org/cgi/content/full/116/25/e569/DC1.