Tumors involving the heart are rare, and the majority of them are benign. Secondary lymphoma with localization to the heart is the third most common malignant heart tumor and is more common, by far, than primary cardiac lymphomas. In patients with human immunodeficiency virus, the risk of development of systemic lymphoma is 60 to 200 times higher than in the general population. Symptoms usually consist of chest pain and dyspnea. Patients can also present with obstructive symptoms, based on the location and size of the tumor, and signs such as elevated jugular venous pressure, peripheral edema, ascites, and hepatomegaly. Transthoracic echocardiography is the initial modality of choice for diagnosis of cardiac lymphomas because it is readily available and helps localize the tumor, but transesophageal echocardiography and magnetic resonance imaging remain the best tests for evaluation. Treatment consists primarily of chemotherapy, and anticoagulation can be used in certain cases where embolization of the tumor is likely. This case review describes a 37-year-old man with past medical history significant for herpes zoster and stage 1 syphilis who presented with complaints of weight loss, intermittent fevers, and vague chest pains of 1-month duration.