Correlation of renal cell carcinoma grade and presence of parasitic vessels on preoperative computed tomography scans.

BACKGROUND: Parasitic (collateral) vessels observed on contrast-enhanced computed tomography (CT) have been associated with aggressive tumor behavior in renal cell carcinoma (RCC). However, their correlation with tumor grade remains insufficiently characterized. AIMS AND OBJECTIVES: To evaluate the association between the presence of parasitic vessels on preoperative CT scans and histopathological tumor grade in patients with RCC. MATERIALS AND METHODS: This retrospective cohort study included 306 patients who underwent nephrectomy for histologically confirmed RCC between January 2016 and December 2024 at a tertiary care center. Preoperative CT scans were independently reviewed for the presence of parasitic vessels. Associations between imaging findings and clinicopathological variables were analyzed using Chi-square and t-tests. Significant variables were entered into multivariate logistic regression analysis. RESULTS: Parasitic vessels were identified in 158 patients (51.6%). Their presence was significantly associated with larger tumor size (>4 cm), higher T stage, lymphovascular invasion, central necrosis, microvascular invasion, rhabdoid features, and higher tumor grade (P < 0.001). Multivariate analysis demonstrated that tumor size >4 cm (AOR 6.920; 95% CI 4.091-11.707), stage 1 and 2 disease, lymphovascular invasion, central necrosis, and grades 1-3 were independent predictors of parasitic vessel presence. CONCLUSION: Parasitic vessels on preoperative CT are significantly correlated with higher tumor grade and adverse pathological features in RCC. Their identification may serve as a noninvasive imaging biomarker for tumor aggressiveness and assist in preoperative risk stratification.