Infiltrating Carcinoma of the Renal Pelvis

Carcinoma originating in the renal pelvis or calyces may invade the renal parenchyma extensively. The resultant parenchymal component may become the dominant feature of the neoplasm, obscuring the source and nature of the original lesion. It appears, however, that these tumors alter the renal vascular pattern in characteristic fashion so that selective renal angiography is helpful in establishing the correct diagnosis. The vascular changes are different and more subtle than those associated with hypernephromas. It is important that neoplasm not be excluded from consideration because of the absence of bizarre tumor vessel formation. It is the purpose of this paper to describe the changes associated with carcinomas arising from the renal pelvis and calyceal system that have infiltrated the renal parenchyma. We have had the opportunity to study 4 such cases, 3 of the transitional-cell type and 1 of the squamous-cell variety. All showed similar arteriographic findings. Roentgen Features These tumors arise from the epithelium of the calyces or renal pelvis and most commonly present as an intraluminal lesion. As the tumor grows, it may obliterate a calyx or produce occlusion of one or more infundibula. In each of the 4 cases, a portion of the calyceal system did not opacify owing to obliteration by the tumor (Figs. 1, A; 2, A; 3, A; and 4, A). In addition, nodular filling defects in the renal pelvis were seen in 3 instances (Figs. 1, A; 2, A; and 3, A). Selective angiography of infiltrating renal pelvic carcinoma demonstrates a relatively hypovascular area within the area of tumor infiltration. Unlike hypernephromas, this finding has been consistently noted with transitional- and squamous-cell carcinomas. In spite of the lack of florid tumor vasculature, on close inspection of the angiograms, enlarged pelvi-ureteric arteries may be identified (1) (Figs. 1, B; 3, B; and 4, B). There is no arteriovenous shunting, pooling of contrast material, or bizarre irregular neovascularization. Not only is there a generalized hypovascularity in the area of the tumor infiltration, but residual parenchymal vessels may be abruptly narrowed or occluded (Figs. 1, B; 2, B; 3, B; and 4, B). Other vessels show segmental or irregular changes in caliber and contour secondary to encasement by tumor. This appearance is comparable to findings noted with other hypovascular tumors, i.e., pancreatic carcinoma, in which changes in normal vessels rather than tumor vessels per se are found.