Metastasizing renal cell carcinoma and acquired renal cystic disease in a hemodialysis patient.

Acquired renal cystic disease is an entity which is characterized by the progressive substitution of the atrophic renal parenchyma by multiple cysts in patients with renal insufficiency. Its main complications are hemorrhage and tumorous degeneration. The case discussed is a 57-year-old patient with terminal renal insufficiency secondary to interstitial nephropathy, who, following 6 years of treatment with hemodialysis and renal transplantation, developed a state of persistent hematuria requiring nephrectomy of the left kidney. Histological study revealed multiple cysts of monostratified epithelium with intracavitary projections, multiform adenomas and multifocal malignant tumorous polymorphism. The patient died in a state of progressive cachexia with pleural and hepatic metastasis.