Ipsilateral retroperitoneal papillary renal cell carcinoma 27 years after simple nephrectomy for a renal abscess: A case report

Figure 1 Magnetic resonance imaging of the abdomen. A: The T2-weighted coronal image shows three distinct oval masses in the left retroperitoneum (indicated by orange arrows), exhibiting a high signal intensity and a well-enhanced pattern; B: The image on the left displays diffusion-weighted transverse images of three retroperitoneal masses (indicated by orange arrows), while the image on the right shows the corresponding gross features of three specimens. The diffusion-weighted transverse images reveal mild restricted diffusion.

Figure 2 Intraoperative findings show a distinct, well-demarcated round mass (black arrow) after dissecting the descending colon (white arrow).

Figure 3 Immunohistochemical results (×100). A: Tumor cells show diffuse cytoplasmic positivity for pan-cytokeratin; B: Vimentin; C: Cytokeratin 7; D: α-methylacyl coenzyme A racemase.

Figure 4 Microscopic findings of hematoxylin and eosin staining. A: Tubulopapillary structures with some microcystic changes (×100); B: Papillary structures associated with accumulation of foamy histiocytes (×100); C: Tubulopapillary structures lined by eosinophilic epithelial cells with high-grade nuclear features of Fuhrman nuclear grade 3-4 (×200); D: Psammomatous calcific bodies scattered over tubular lumina and interstitial stroma (×200).