Venous Tropism in Renal Cell Carcinoma: A Rare Imaging Presentation.

Renal cell carcinoma (RCC) is one of the most prevalent malignancies in adults. Accurate staging and assessment of tumor extent are critical for effective management. RCC often demonstrates a tendency for venous invasion, commonly extending into the renal vein and inferior vena cava. However, RCC extending into the gonadal veins is an uncommon manifestation. In this report, we present the imaging features of a 62-year-old woman presented with left flank pain. The ultrasound examination revealed a large hyperechoic mass in the left renal fossa, replacing almost the entire left kidney with the contiguous extension of the tumor into the left renal vein and ovarian vein. Color Doppler showed the presence of flow within the thrombus, confirming the presence of a malignant thrombus. Contrast-enhanced CT examination revealed a large heterogeneously enhancing mass in the left kidney with the contiguous extension of tumor thrombus in the left renal vein, IVC, and into the left ovarian vein. This report highlights how imaging techniques can be instrumental in detecting and characterizing rare but significant tumor extensions, which can have crucial prognostic implications for overall patient management.