Active malignancy in patients with renal vein thrombosis: influence upon clinical course and survival.

Background: Renal vein thrombosis (RVT) is a rare event with myriad clinical manifestations. Published experience regarding the clinical course and management of RVT in patients beyond the neonatal period is limited to case reports and small case series.

Methods: A multicenter retrospective review of consecutive admitted patients with diagnosed RVT between January 2000 and May 2015 at three different university hospitals.

Results: Thirty-nine patients (53.8 % men and 46.2 % women) were included. Median age was 58 years. Malignancy (n = 19, 48.7 %), nephrotic syndrome (n = 8, 20.5 %) and infection (n = 5, 12.8 %), were the most common underlying conditions. Compared to non-cancer patients, patients with active cancer tended to be significantly older (mean age 63 ± 18 vs. 37 ± 22 years, P = 0.001) and presented with non-acute symptoms (P = 0.01) and unrevealing physical findings (P = 0.02). Thrombosis extension beyond the renal vein occurred in 69.2 % of cases and was more common in cancer patients (P = 0.001). Anticoagulation therapy was administered in 71.8 % of patients leading to resolution of thrombus in most cases (30/32 patients, 94 %) during follow-up evaluation. There were six recurrent thrombotic events during a mean follow-up of 35 ± 43 months. Nine patients (28 %) died during follow-up, all of them with malignancy.

Conclusion: Active cancer is the most common cause of RVT and should be excluded when RVT is diagnosed. Clinical course of RVT in cancer patients is more indolent and diagnosis requires high index of suspicion. Survival rates are governed by the presence of malignancy.