Renal Abscess Complicated by Renal Vein Thrombosis Mimicking Clinical Stage T3a Renal Cell Carcinoma

Abstract

Renal abscesses accompanied by a renal vein thrombosis (RVT) may have a similar appearance to clinical stage T3a renal cell carcinoma (RCC) on computed tomography (CT) imaging. RVTs are rare clinical findings that more commonly occur in adults with malignant renal tumors or nephrotic syndrome. A 71-year-old woman with risk factors for both renal infection and RCC was found to have a heterogeneous mass with irregular borders and areas of contrast enhancement on CT imaging. A two-week course of antibiotic and anti-coagulant treatment was prescribed with close follow-up. Urine culture eventually grew greater than 100,000 colonies of Escherichia coli. Repeat imaging after six weeks revealed resolution of the mass and the RVT. This patient's case emphasizes that although the findings of RVT and renal mass more commonly point to the diagnosis of malignancy, infections many present in a similar manner but require substantially different treatment. Close follow-up with repeat imaging is imperative to differentiate malignancy from infection or other causes.