case_images: PMC11327074_01
case_images: Abdominal pelvic enhanced computerized tomography (CT) and pathology of the left kidney and retroperitoneal masses. (A) Heterogeneously enhancing mass in the middle of the left kidney with necrotic cysts and bleeding (yellow arrows). (B) Non-uniform enhanced mass with central necrosis in the retroperitoneum (yellow arrows). (C) Renal clear cell carcinoma of the left renal mass. (D) Schwannoma of the retroperitoneal mass. (E) Retroperitoneal mass staining strongly positive for S-100 on immunohistochemistry (IHC). (F) Retroperitoneal mass staining strongly negative for CD117 on IHC.
case_images: fneur-15-1450217-g001.jpg
case_images: PMC11327074_01_fneur-15-1450217-g001.jpg
case_images: fig1
case_images: Abdominal pelvic enhanced computerized tomography (CT) revealed a 3.9 cm*3.7 cm*3.3 cm protuberant mass with a rich blood supply in the middle of the left kidney, containing necrotic cysts and hemorrhage (Figure 1A). Additionally, a 4.7 cm*4.5 cm*3.8 cm heterogeneous enhanced retroperitoneal mass with central necrosis was observed, considered to be metastatic lymph nodes (Figure 1B). Postoperative pathology revealed that the left renal mass was renal clear cell carcinoma (Figure 1C), graded as International Society of Urological Pathology (ISUP) grade 2. Pathological examination of the retroperitoneal mass showed spindle cell tumors with an uneven distribution of cells under microscope (Figure 1D). Immunohistochemistry (IHC) demonstrated positive staining for S-100 (Figure 1E) while CD117 (Figure 1F), CD34 and DOG-1 were negative.