Differential Diagnosis

• Single most likely diagnosis
  • Simple renal cysts: The presence of bilateral renal cysts, particularly with the described sizes and locations, is most consistent with simple renal cysts, which are common and usually benign.
• Other Likely diagnoses
  • Polycystic kidney disease (PKD): Although less likely given the limited number of cysts, PKD could be considered, especially if there's a family history. However, the presence of only two cysts and the absence of other characteristic findings (such as numerous cysts, enlarged kidneys, or liver cysts) makes this less likely.
  • Renal stone disease: The presence of two small renal stones in the left kidney supports this diagnosis, which is common and can be associated with cysts.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Renal cell carcinoma (RCC) with cystic components: Although the report mentions no evidence of solid masses, it's crucial to consider RCC, especially if the cysts have complex features or if there are other suspicious findings not mentioned. RCC can sometimes present with cystic components.
  • Infection or abscess: While the report does not suggest infection, it's essential to consider this possibility, especially if the patient presents with symptoms like fever, flank pain, or urinary tract infection symptoms.
• Rare diagnoses
  • Multicystic dysplastic kidney (MCDK): This condition is typically identified in childhood and involves non-functional kidney tissue being replaced by multiple cysts. It's less likely in this scenario given the patient's kidneys are described as having normal position, orientation, and preserved parenchyma.
  • Tuberous sclerosis complex (TSC): This genetic disorder can lead to the development of renal cysts and angiomyolipomas. The presence of only two cysts without mention of other characteristic TSC findings (like angiomyolipomas) makes this diagnosis less likely but should be considered if other systemic symptoms or family history suggest TSC.