Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is the major RCC subtype in patients with end-stage renal disease, specifically those with ACD on dialysis. Three patients with a total of eight tumors have been selected. The aim of this study was to analyze clinicopathologic, immunohistochemical, and prognostic features of eight ACD-RCCs. Three patients with end-stage renal disease (ESRD) were in the age range of 34-45 years and being treated with hemodialysis. All eight tumors were resected by radical nephrectomy. Two patients had a single ACD-RCC, while one patient had bilateral and multifocal ACD-RCCs. Microscopically, combinations of architectural patterns were identified in all tumors. Intracytoplasmic and intraluminal vacuoles, eosinophilic granular cytoplasm, and prominent nucleoli were universal characteristics of these tumors. Atypical cysts were present in three out of four resected kidneys. Immunohistochemistry (IHC) staining revealed all tumors were strongly and diffusely positive for pan-cytokeratin and α-methylacyl-CoA racemase and variably positive for CK7, CD10, PAX8, EMA, vimentin, cytokeratin, high molecular weight cytokeratin (CK HMW). All cases were negative for Napsin A, CK20, CD117, and CD57. After an average follow-up of 27.5 months (range 3-54 months), all our patients are alive without neoplastic (metastatic or recurrent) disease. Our study supports the finding that ACD-RCC has specific morphologic features and a broad spectrum of architectural patterns. We have found that the immunoprofile of ACD-RCC is distinct from that in other RCCs; however, nonspecific and interpretation of microscopic features in the context of the clinical history can aid the diagnosis. We confirm also the favorable prognosis in ACD-RCC.
Keywords: Acquired cystic disease-associated renal cell carcinoma; acquired cystic kidney disease; end-stage renal disease; immunohistochemistry; renal cell carcinoma.