“…Although some cases of these negative angiographic findings are difficult to diagnose as RCC, the introduction of new imaging modalities, such as the computed tomography (CT) scan, magnetic resonance imaging (MRI), and ultrasonography, has led to substantial improvements in the accuracy of diagnosis. 2 The present study assessed the histopathological features of hypovascular or avascular RCC, and clarified these non-typical RCCs, based on the tumor-related vasculature, histological organization, and cell types of the tumor.…”