Renal tumors in end-stage renal disease: A comprehensive review.

The incidence of end-stage renal disease has increased owing to the greater prevalence of patients with chronic kidney disease and diabetes mellitus. End-stage renal disease is usually accompanied by acquired cystic disease and is a risk factor for renal cell carcinoma. The present review discusses the etiology of renal cell carcinoma in end-stage renal disease patients, focusing on two unique renal cell carcinoma histological subtypes: acquired cystic disease-associated renal cell carcinoma and clear cell papillary renal cell carcinoma. Acquired cystic disease-associated renal cell carcinoma occurs almost exclusively in patients who underwent hemodialysis, especially long-term (>10 years) hemodialysis. Its histology is distinctive: a cribriform or sieve-like architecture with intra- or intracystic lumina; tumor cells containing abundant eosinophilic cytoplasm and large nuclei with prominent nucleoli; and most notably, calcium oxalate crystal deposition. Recognition of the crystals is critical for diagnosing acquired cystic disease-associated renal cell carcinoma. Acquired cystic disease-associated renal cell carcinoma typically has an indolent clinical course, except in cases with sarcomatoid components. Clear cell papillary renal cell carcinoma also has an indolent course (no cases involving metastasis have been reported to date), and its features resemble those of both clear cell renal cell carcinoma and papillary renal cell carcinoma. Unlike acquired cystic disease-associated renal cell carcinoma, which occurs only in end-stage renal disease patients, clear cell papillary renal cell carcinoma occurs in non-end-stage renal disease patients as well. Additional renal tumors in end-stage renal disease patients include anastomosing hemangiomas. Long-term hemodialysis worsens the prognosis of end-stage renal disease patients with renal cell carcinoma, regardless of its original histological subtype, presumably by inducing oxidative stress and sarcomatoid transformation.