Diagnosis of a primary cardiac B-cell lymphoma

Abstract

A 56-year-old man with acute onset of sepsis and ventricular fibrillation was successfully resuscitated after his wife had noticed him breathing heavily in the night. The arrhythmia did not persist after curing the sepsis. However, during the diagnostic workup, echocardiography detected a right-ventricular mass (Image 1A). Cardiac magnetic resonance imaging identified the mass being a perfused tumor without attached thrombus (Image 1B; arrowheads). The tumor's gadolinium-enhancement was somewhat heterogeneous with a small central hypointensity shown in Image 1B (arrow). A biopsy was taken during right-heart catheterization that depicted the tumor well (Image 1C). Histologically, the tumor consisted of multiple atypical lymphoid cells with large nuclei (Image 1D; Giemsa staining). Additional immunostaining revealed a CD20-positive B-cell lymphoma (Image 1E) with a high proliferation rate. The staging revealed no other malignancies, leading to the diagnosis of a primary cardiac diffuse large B-cell lymphoma (DLBCL). The patient received dose-dense chemotherapy according to the R-CHOP-14 protocol, consisting of six cycles of cyclosphosphamide, doxorubicin, vincristine, and prednisone given at 14-day intervals. Each cycle was preceded by immunotherapy with the monoclonal antibody rituximab that is targeted against CD20-positive B-cells (Image 1E). The cardiac lymphoma resolved, and the patient is now in remission since more than 3 years. Diagnosis of a primary cardiac B-cell lymphoma: (A) echocardiography identified a mass in the right ventricle; (B) cardiac magnetic resonance imaging showed that this mass was gadolinium-enhancing and thus a perfused vital tumor (arrowheads), the contrast-enhancement was somewhat inhomogeneous with a central hypointensity (arrow), the tumor had contact to the trabeculae of the right ventricle (T), and some pericardial effusion was visible at the apex of the heart (*); (C) a minimally invasive transcatheter biopsy was obtained during right-ventricular catheter angiography; (D) Giemsa staining showed atypical lymphoid cells with large nuclei; and (E) the CD-20 immunostaining was positive. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] In persons without immunodeficiency, a primary cardiac lymphoma is a rare malignancy, accounting for about 1.3% of primary cardiac tumors [1]. Histologically, most cases are DLBCLs [1, 2]. Echocardiography generally is the initial imaging modality. Magnetic resonance imaging is well suitable for obtaining more detailed information about the tumor's localization, mobility, vitality, infiltration of cardiac or pericardial structures, and attached thrombus that might embolize. For the differential diagnosis of magnetic resonance imaging, isointensity of the tumor to the normal myocardium on T1- and T2-weighted images and heterogeneity of gadolinium-enhancement have been described for primary cardiac lymphoma and not for other cardiac neoplasms; however, histology is required for definite diagnosis [3]. Modern therapy, such as chemotherapy with the addition of immunotherapy, has improved the individual prognosis [2, 4].