Renal vein aneurysm secondary to renal cell carcinoma.

Venous aneurysms are rare entities, especially those involving the visceral veins. Renal venous aneurysms have been documented in isolated case reports and we present one such case. An adult male presented with flank pain and hematuria. The initial ultrasound abdomen was suggestive of a right renal mass with a venous varix of ipsilateral renal vein. Computed tomography (CT) showed a high-complexity mass lesion in the right kidney with tortuous varices in the perinephric space and focal aneurysmal dilatation of the right renal vein. No arteriovenous fistula (AVF) or malformation was identified, but attenuation values suggested arteriovenous shunting. A biopsy of the mass was suggestive of clear cell carcinoma. The patient underwent digital subtraction angiography and embolization, followed by a total nephrectomy. However, the patient presented with brain metastases later and eventually succumbed to the illness. Renal venous aneurysms may develop secondary to venous hypertension, thrombosis, or renal AVFs. CT can help confirm the diagnosis, assess size, estimate graft length if required, and identify possible causes and potential complications. Known complications include rupture, thrombosis, and pulmonary thromboembolism. Treatment options include reconstruction of the renal vein with grafts, endovascular treatments such as embolization if there is an AVF and nephrectomy. Visceral venous aneurysms can cause life-threatening complications that treating physicians must be aware of. Clear-cell renal cell carcinoma is associated with arteriovenous shunting, which can cause venous hypertension, varices, and, as seen in our case, renal vein aneurysms.