The kidney shows reduced cortex with no distinct corticomedullary junction. The cortex is pale and riddled with numerous cysts. To the right is a distinct hemorrhagic nodule which represents an admixture of organizing hemorrhage and focal carcinoma. These tumors may be solitary, or, in about 50% of cases, multiple.
Most of the cyst lining consists of a non-layered epithelium with abundant clear or eosinophilic cytoplasm.
Much of the nodule also shows hemorrhage in the lumen.
Intratumoral calcium oxalate crystals are numerous; tumor cells show marked eosinophilic granular cytoplasm
The crystals are within the stroma and epithelial cells themselves; tumor nuclei are round to oval.
Other areas may show intercellular lumen like spaces, imparting a cribriform appearance.
This other focus tumor show clear cytoplasm and basally oriented nuclei.
Some tumors may harbor higher grade nuclei (left).
Patients with end stage renal disese (ESRD), and in particular those with acquired renal cystic disease (ARCD), are at increased risk of developing renal cell carcinoma. Acquired renal cystic disease specifically refers to bilateral cystic renal changes occurring in patients with end-stage kidney disease resulting from nonhereditary renal cystic disease on long-term dialysis.
The risk of cancer is directly related to the presence of cysts (Choyke), with an incidence of neoplasia of around 5% to 25%. The most common tumors in the setting of ARCD include papillary RCC and a tumor unique those with ARCD -- designated renal cystic disease associated RCC. These latter tumors frequently contain intratumoral oxalate crystals and are positive for AMACAR but negative for keratin 7.
Compared with sporadic RCC, ACKD-associated RCC is characterized by young patient age, male predominance, frequent multicentricity and bilaterality (Truong). Risk factors for tumor development include male sex, duration of dialysis, and kidney weight but not type of dialysis (Truong). Most tumors (86%) are asymptomatic, although hematuria may occur (Truong).
Compared with sporadic RCC, ACKD-associated RCC shows less aggressive behavior (Truong).
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Bisceglia M, Galliani CA, Senger C, Stallone C, Sessa A. Renal cystic diseases: a review. Adv Anat Pathol. 2006 Jan;13(1):26-56.
Truong LD, Choi YJ, Shen SS, Ayala G, Amato R, Krishnan B. Renal cystic neoplasms and renal neoplasms associated with cystic renal diseases: pathogenetic and molecular links. Adv Anat Pathol. 2003 May;10(3):135-59.