30 April 2026
: Case report 
Clear Cell Renal Cell Carcinoma in a 60-Year-Old Man Arising From Congenital Left-Sided Ectopic Right Kidney (Crossed Fused Renal Ectopia) With Invasion Into the Contralateral Kidney
Challenging differential diagnosis, Unusual or unexpected effect of treatment, Educational Purpose (only if useful for a systematic review or synthesis), Rare coexistence of disease or pathology
Shakhawan Hama Amin Said ABG 1,2*, Mzhda Sahib Jafaar AB 1, Goran M. Raouf Abdulqader ABD 3, Zana Ezzat Hama Karim AB 4, Kewan Hussein Shekh Faraj
ABCDEF 4, Ali Mzhda Mohammed Ali ADEF 5, Aland Salih Abdullah ADEF 1, Diyam Dlshad Hassan DEF 1, Ahang Mohammed Abdulrahman DEF 4
DOI: 10.12659/AJCR.952016
Am J Case Rep 2026; 27:e952016
Figure 8 Histopathologic and immunohistochemical features of clear cell renal cell carcinomaMicroscopic examination reveals features of clear cell renal cell carcinoma (RCC): (A) Clear cell RCC, World Health Organization/International Society of Urological Pathology grade 3, with prominent eosinophilic nucleoli. (B) Tumor invasion at the interface between the ectopic right kidney and the normal left kidney, with tumor islands (red arrow), fibrovascular stroma (white arrow), and adipocytes (black arrow). (C) Carbonic anhydrase IX immunostaining showing strong membranous positivity in tumor cells. (D) Fumarate hydratase immunostaining demonstrating diffuse granular cytoplasmic positivity. (E) Tumor cells with granular eosinophilic cytoplasm and thin-walled vascular networks.