Primary malignant lymphoma of the right atrium resulting in superior vena caval syndrome in an HIV-positive patient: depiction at multislice computed tomography and magnetic resonance imaging.

An HIV-positive 32-year-old male presenting with superior vena cava syndrome underwent multislice computed tomography (MSCT) and magnetic resonance imaging (MRI), which showed a large tumor in the right atrium, which extended to the superior vena cava. Pathologic examination revealed that the mass was consistent with B cell-type malignant lymphoma. The tumor size markedly decreased after the initiation of chemotherapy and patient recovery has been uneventful for 1 year.