Previous reports showed that some patients with renal cell carcinoma (RCC) and renal vein tumor thrombus (RVTT) were misdiagnosed pre-operatively. To improve the accuracy of this diagnosis, the clinical characteristics of RCC with missed RVTT diagnosis were analyzed.
We retrospectively reviewed RCC patients with RVTT between January 2000 and December 2015. The survival analysis was estimated using the Kaplan-Meier method. The Cox proportional hazard models were applied to identify risk factors.
The missed diagnosis rate of RVTT in RCC was 30.5%. In multivariate analysis, maximal tumor diameter, tumor located in the middle part, renal vein contrast agents filling insufficiently and tumor with collateral vessels (odds ratio = 1.22, 1.35, 1.25, 1.22; and  = .034, .003, .015 and .037, respectively) were independent predictors of missed RVTT diagnosis. A missed-diagnosis score was presented as area under curve of 0.852 ( < .001). Moreover, the missed diagnosis group had favorable prognosis, and tumor with collateral vessels was an independent prognostic indicator of poor overall survival time (hazard ratio = 1.15,  = .025).
This was the first study exploring clinical features as predictors of missed RVTT diagnosis. The possibility of complicating tumor thrombus should be considered when there is pre-operative presence of tumor with large diameter, renal tumor in the middle part, renal tumor with collateral vessels and renal vein contrast agents filling insufficiently. Patients with three points in missed-diagnosis scoring suggested a high possibility of missed RVTT diagnosis, and tumor with collateral vessels indicated poor prognosis.