Inferior vena cava (IVC) thrombosis is a rare medical condition. Suppurative thrombophlebitis of the IVC is even a more uncommon subtype of IVC thrombosis and is mostly associated with IVC filters or venous catheters. We describe a 66-year-old man with persistent fever and history of pyonephrosis secondary to transurethral lithotripsy 1 month before recent admission. Computed tomography scan of the chest and abdomen revealed a filling defect in the IVC protruding into the right atrium. Transesophageal echocardiogram (TEE) revealed a large mass at the origin of the IVC entering into the right atrium, suggestive of a clot. Diagnosis of suppurative thrombophlebitis of the IVC secondary to a retroperitoneal abscess was made, and intravenous antibiotic therapy for 6 weeks without anticoagulation conferred ample thrombus resolution. Follow-up TEE in week 16 showed no residual thrombus in the IVC.
