Abstract Body (Do not enter title and authors here): Description of Case:
A 78-year-old male with past medical history of atrial fibrillation, hypertension, and recent admission for post-viral pericardial effusion status-post pericardiocentesis initially presented for a syncopal episode while climbing a flight of stairs. Transthoracic echocardiography (TTE) demonstrated marked asymmetric myocardial wall thickening involving the inferior, lateral, and posterior myocardial walls, concerning for an infiltrative process (Figure 1A). Cardiac magnetic resonance imaging (MRI) demonstrated 3.8cm thickening of the left ventricular (LV) and right atrial (RA) wall, consistent with an infiltrative malignancy (Figure 1B) that was again visualized on cardiac CT (Figure 1C). Positron emission tomography-computed tomography (PET-CT) revealed fluorodeoxyglucose (FDG) avidity in the right testis (2A), suspicious for possible testicular lymphoma or sarcoma, in addition to radiotracer uptake in the RA and LV (Figure 2B). The patient then underwent orchiectomy, from which pathology demonstrated diffuse large B-cell lymphoma (DLBCL) (Figure 3A-3C).

Following his diagnosis, the patient was started on etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab (EPOCH-R) for primary testicular lymphoma with presumed cardiac metastases, in addition to intrathecal methotrexate. Repeat TTE following completion of his chemotherapy course was without any recurrence of intracardiac mass.

Discussion:
Intracardiac masses can be further defined as tumor, thrombus, or vegetation. Various modalities of cardiac imaging, including echocardiography, cardiac MRI, cardiac CT, and PET assist in characterizing intracardiac masses. Amongst intracardiac tumors, the vast majority are metastases from alternative primary sites of malignancy. The remaining are primary intracardiac tumors, of which the majority are benign.

Testicular lymphoma is a rare entity, comprising only 9% of all testicular cancers. Of those, 80-90% of testicular lymphomas are consistent with DLBCL. While testicular DLBCL often metastasizes to contralateral testes, central nervous system, skin, and pleura, cardiac involvement is much rarer and often observed in immunocompromised patients. Fortunately, most patients respond well to systemic chemotherapy.