Renal cyst

• simple renal cysts typically have thin walls with no calcification, septation or enhancement shown on contrast studies. Solitary simple cysts are common and are often diagnosed incidentally
  
  
• "Simple" cysts are best defined using sonographic criteria. These include:
  • (1) absence of internal echoes,
  • (2) posterior enhancement,
  • (3) round/oval shape and
  • (4) sharp, thin posterior walls.
  • when all of the criteria are met, the cyst is benign and no follow-up is required
    
    
• in the minority of patients who are symptomatic who have a simple renal cyst, pain is the most frequent complaint
• management
  • symptomatic simple renal cysts can be managed with analgesic medication, needle aspiration (with or without administration of a sclerosant) and open surgical cyst deroofing if aspiration is unsuccessful at relieving symptoms in the long term. In some patients, a nephrectomy may be necessary
  • NICE suggest laparoscopic deroofing as a management option for symptomatic simple renal cysts
    • laparoscopic deroofing is not used if there is any suspicion of malignancy
      • asymptomatic cysts do not usually require any treatment
      • note that the management of polycystic kidney disease is different from that of simple renal cysts

Reference:

1. Weber, TM. Sonography of benign renal cystic disease: Ultras Clin 2006;1:15-24.
2. NICE (July 2007).Laparoscopic deroofing of simple renal cysts.