Summary: This case describes incidental findings in a 50-year-old male presenting
with a fever, which earlier underwent an orthotopic liver transplant.
Right renal vein varix
Computed tomography (CT) demonstrated a focal enhancing ovoid density
adjacent to the right renal hilum continuous with the right renal vein.
It had an enhancement pattern similar to that of the right renal vein.
A frequent incidental finding, renal varices can be idiopathic or
associated with either renal vein thrombosis, obstruction, or congenital
anomalies of inferior vena cava, as well as azygous or portal
hypertension.1,2 Idiopathic renal varices demonstrate left predominance, with an incidence of 6% to 10% in renal donors on phlebography.1,3
The etiology of left predominance in idiopathic cases has been
postulated to be stretching of the renal vein over the aorta and
compression between the superior mesenteric artery (SMA) and the aorta,
known as the nutcracker phenomenon.1,4 In addition, extensive collaterals from other organs and weakness of the vein wall may be contributing factors.1
Furthermore, the absence of gonadal vein valves and abnormal
collaterals between the renal and gonadal veins have been suggested as
contributing factors.2 In 31% of renal vein varix there is associated saphenous vein varicosity.
Extrarenal varices are more common than intrarenal.5 The latter may have calcifications and can simulate renal masses, especially if thrombosed.5,6
The differential of renal varix includes renal or urothelial neoplasm,
hemangioma, blood clots, pyelo-ureteritis cystica, leukoplakia,
tuberculosis, and radiolucent calculi.4,5 Failure to recognize this characteristic appearance may lead to unnecessary nephrectomy.6
the excretory urogram may demonstrate external compression of the renal
pelvis or proximal ureter by the varix, phlebography with or without
epinephrine is the historic diagnostic modality of choice.1,6 However, contrast enhanced CT or magnetic resonance imaging (MRI) detect renal varices noninvasively.5 CT demonstrates attenuation matching and is continuous with that of renal vein on pre- and post-contrast images.5
MRI demonstrates signal voids on the axial spin echo and T2-weighted
images, and high signal on the modified gradient echo and phase contrast
with gadolinium imaging, similar to that in other veins.5
The sagittal plane is especially useful for evaluation of nutcracker
syndrome. In these patients, MRI demonstrates the acute take-off angle
of the SMA from the aorta.7 It could be used to diagnose this
condition noninvasively, rather than demonstrating the pressure
gradient between the renal vein and the IVC during venography.2 In addition, Technetium-99m red blood cells have been used to demonstrate pooling in a case of renal varix caused by hematuria.3
Pain with renal varices is extremely rare. Varices are typically asymptomatic and only infrequently associated with hematuria.5,8 Whether renal varices actually cause hematuria is controversial.5
Nevertheless, surgical ligation or embolization are frequently used in
patients with hematuria and/or pain but no other explanation.5 The transposition of the left renal vein to a more caudal location has been successfully used in nutcracker syndrome.7 Other complications include partial or complete obstruction and renal stone formation.5
Renal vein varices are a frequent incidental finding on CT or MRI. Renal
varices may mimic renal masses especially on noncontrast CT scans. The
continuity with renal vein and similarity to vein appearance on all
imaging modalities are important differentiating factors. Complications
are rare, and include hematuria, obstruction, and stone formation.
Surgical ligation or embolization may be used to treat varices
associated with pain or hematuria.
- Beckmann CF, Abrams HL. Idiopathic renal vein varices: Incidence and significance. Radiology. 1982;143(3):649-652.
- Weiner SN, Bernstein RG, Morehouse H, Golden RA. Hematuria secondary to left peripelvic and gonadal vein varices. Urology. 1983; 22(1):81-84.
- Rendak I, Pison C, Drouin G. Demonstration of renal varices using
technetium-99m red blood cells in the investigation of recurrent
macroscopic hematuria. Clin Nucl Med. 1987;12(11):861-863.
- Trambert JJ, Rabin AM, Weiss KL, Tein AB. Pericaliceal varices due to the nutcracker phenomenon. AJR Am J Roentgenol. 1990;154(2):305-306.
- Deibler AR, Nadig SN, Curry N, Bissada NK, Hull GW. Intrarenal varix presenting as an enhancing renal mass with calcifications. J Urol. 2001;166(3):997-998.
- Curry NS, Frangos DN, Stanley JH. Thrombosed right renal vein varix simulating a renal pelvic mass. Urol Radiol. 1987;9(1):36-38.
- Hohenfellner M, Steinbach F, Schultz-Lampel D, et al. The nutcracker
syndrome: New aspects of pathophysiology, diagnosis and treatment. J Urol. 1991;146(3):685-688.
- Nielsen PT, Nielsen SM. Idiopathic renal vein varicosities. Presentation of two cases and a brief review of the literature. Scand J Urol Nephrol. 1984;18(1):91-95.