Gonadal vein tumor thrombosis due to renal cell carcinoma.

Renal cell carcinoma (RCC) had a tendency to extend into the renal vein and inferior vena cava, while extension into the gonadal vein has been rarely reported. Gonadal vein tumor thrombosis appears as an enhancing filling defect within the dilated gonadal vein anterior to the psoas muscle and shows an enhancement pattern identical to that of the original tumor. The possibility of gonadal vein thrombosis should be kept in mind when looking at an imaging study of patients with RCC.

INTRODUCTION

Renal cell carcinoma (RCC) had a tendency to extend into the renal vein and inferior vena cava (IVC),[1] while gonadal vein tumor thrombosis (GVT) has been rarely reported.[2345] GVT is a rare entity, typically seen as a complication of postpartum endometritis, pelvic inflammatory disease, and gynecologic surgery. Even among patients with malignancy, GVT is typically a bland thrombus rather than a tumor thrombus.[6]

CASE

A 57-year-old female presented with back pain and paraparesia, leading to the incidental discovery of a heterogeneous large mass involving the left kidney with vertebral, liver and pulmonary metastases, and invasion to the IVC and renal vein as well as ovarian vein tumor thrombosis, which was documented in contrast-enhanced CT by an enhancing low attenuation filling defect within dilated left ovarian vein [Figures 1 and 2]. CT guided biopsy from a vertebral lesion confirmed metastasis from renal cell carcinoma. After angiographic embolization for this unresectable tumor, external radiotherapy was administered for palliation. Several months later, she died due to extensive metastatic disease to brain, lung, liver, and bones.

Figure 1

An enhancing left renal mass containing necrosis and calcification is seen invading left renal vein (white arrows in a and b) and inferior vena cava (black arrows) with metastatic lesions of T12 vertebra. Tumor thrombosis of left ovarian vein (arrows in c and d) is evident as enhancing filling defect within dilated vein

Figure 2

Coronal reformatted computed tomography images show a heterogeneous mass in the left side of the aorta and thrombosis of the inferior vena cava (curved arrow) and left ovarian vein (white arrow) with enhancement pattern similar to the mass

DISCUSSION

Ovarian veins originate from the plexus in the broad ligament near the ovary and fallopian tube and communicate with the uterine plexus, then course anterior to the psoas muscle and the ureter. The left gonadal vein drains into left renal vein and therefore the left renal tumor can extend retrograde into the left gonadal vein. Diagnosis of GVT is a challenging issue and is usually underdiagnosed, especially in the nonpostpartum patients who do not show typical manifestation, including lower abdominal or flank pain, fever, and a deep tender mass. Contrast-enhanced multidetector CT is the most reliable diagnostic modality. GVT typically presents as a filling defect in a tubular structure (dilated ovarian or testicular vein) anterior to the psoas muscle with a central round low-attenuation center and peripheral higher attenuation rim. Enhancement of this filing defect indicates that it is a tumor thrombus rather than a simple bland thrombus. The enhancement pattern will be identical to that of the original tumor. Dilatation and tortuosity of pelvic veins is a common associated finding.

Unlike postpartum or post pelvic surgery GVT, GVT associated with malignancy may be asymptomatic.[6] The possibility of GVT should be kept in mind when looking at an imaging study of patients with RCC, in whom tumor thrombosis of ovarian vein is a sign of more advanced disease and may be associated with a poor prognosis.