Ultrasonography and doppler diagnosis in a rare asymptomatic case of renal cell carcinoma associated with renal vein thrombosis

Renal cell carcinoma (RCC) is the primary malignant adenocarcinoma that is derived from the renal tubular epithelium and is the most common malignant renal tumor. The peak age of occurrence is 50–70 year. Cigarette smoking and dialysis-related cystic disease are the most common risk factors. Almost half of all identified RCCs are found incidentally on imaging performed for other purposes. On grayscale ultrasound (US), they appear solid or partially cystic and may be hyper, iso, or hypoechogenic to the surrounding renal parenchyma. The tumor pseudocapsule can sometimes be visualized with US as a hypoechoic halo. Sometimes, the tumor may produce thrombosis of ipsilateral renal vein which on grayscale US show renal enlargement with hypoechoic cortex from edema (early phase) and decreasing size and increased echogenicity (late phase). On Doppler visualization of thrombus within the lumen is possible. Early diagnosis of this tumor with precise localization of thrombus extent is important for planning the further course of management. We present a rare case of RCC, without any symptom of hematuria.