Acquired Cystic Kidney Disease Workup

• Ultrasonography

  • Initial imaging studies include ultrasonography of the kidneys. Detecting acquired renal cystic disease in end-stage renal disease (ESRD) may be difficult using ultrasonography because of the complexity of the cysts and the increased echogenicity of the kidneys in ESRD. Differentiating between acquired renal cystic disease and ADPKD may occasionally be difficult, and the distinctive features of acquired renal cystic disease are renal size (not usually increased) and the normal parenchyma distinguishable between cysts (see the Table in Physical). Acquired cystic kidney disease. Patient with end-stage renal disease (ESRD) on maintenance hemodialysis presented with macrohematuria. Ultrasonogram showing numerous cysts in the right kidney and previous cysts in the left kidney.
  • Sonography is used more often than CT scanning as the initial screening method. Sonography is better than CT scanning to differentiate a hemorrhagic cyst because almost all hemorrhagic cysts appear isodense or slightly hyperdense on CT scanning. However, clot formation in the cystic cavity appears as an echoic mass by sonography, and dynamic CT scanning is required for differentiation of clot formation from renal cancer.
• CT scanning with contrast

  • Early enhancement with contrast is superior to ultrasonography for detecting renal cancer. CT scanning is the best imaging technique to establish a diagnosis of cancer. The presence of a small renal cell carcinoma may be suspected if a CT scan shows a mass with contrast enhancement.
  • Although CT scanning is useful to clinically diagnose acquired renal cystic disease, acquired cysts in patients before dialysis may be difficult to diagnose because these cysts are usually small. Acquired cystic kidney disease. A 39-year-old man on dialysis for longer than 10 years with acquired renal cystic disease (ARCD). CT scan showed a mass in the lower pole of the right kidney. Fine-needle aspiration cytology (FNAC) of the lesion showed renal cell carcinoma. The patient underwent nephrectomy. Acquired cystic kidney disease. A 66-year-old man with acquired renal cystic disease (ARCD) had a mass in the lower pole of the right kidney. CT-guided biopsy proved the mass to be renal cell carcinoma. This patient also had type II dissection of the aorta.
• Gadolinium-enhanced magnetic resonance imaging (MRI): MRI is useful in patients who cannot tolerate CT scanning with contrast.

• No other test is specific to aid in the diagnosis of acquired renal cystic disease, and patients require investigations related to renal failure.

• Fine-needle aspiration of equivocal lesions to rule out malignancy is required.

Grossly, the cysts are usually smaller than 0.5 cm in maximal dimension but may attain sizes of 2-4 cm. They affect both the renal cortex and the medulla.

Many cysts contain a single layer of cuboidal epithelial cells; however, many kidneys also contain atypical cysts characterized by a multilayered epithelial lining. There appears to be a histologic continuum from cysts lined with single-layered epithelia, to those with multilayered epithelia, to renal adenoma and carcinoma. Most acquired cysts originate from the proximal tubule. Oxalate crystal deposition is predominant in the cyst walls and the renal interstitium in acquired renal cystic disease.

If renal malignancy is diagnosed, then other investigations, including chest radiography, are required to rule out distant metastasis.