Differential Diagnosis

The patient's presentation with a history of kidney stones on the left side, new onset of low elevated microalbumin and urobilinogen levels, slight protein, and leukocytes in urine, along with slight edema in the ankles (more pronounced on the left foot), suggests a range of potential diagnoses. These can be categorized as follows:

• Single Most Likely Diagnosis

  • Chronic Kidney Disease (CKD) with Possible Left Kidney Damage: The history of kidney stones, especially on the left side, could have led to chronic damage, resulting in the observed urinary abnormalities and edema. The presence of microalbumin and slight proteinuria supports this diagnosis, as these are indicators of kidney damage.

• Other Likely Diagnoses

  • Pyelonephritis or Interstitial Nephritis: Given the patient's history of kidney stones, which can obstruct urine flow and increase the risk of infection, pyelonephritis (infection of the kidney) or interstitial nephritis (inflammation of the spaces between the kidney tubules) could explain the leukocytes in the urine and the edema.
  • Nephrotic Syndrome: Although less likely given the "slight" proteinuria, nephrotic syndrome could be considered, especially if the edema is significant. However, the degree of proteinuria would typically be much higher.
  • Left Renal Vein Thrombosis: This condition could cause edema, particularly if it affects the left leg more, due to the obstruction of blood flow from the left kidney. It's a consideration, especially in the context of nephrotic syndrome or severe kidney disease.

• Do Not Miss Diagnoses

  • Renal Cell Carcinoma: Although rare, kidney cancer could explain the patient's symptoms, especially if a tumor is obstructing urine flow or causing chronic kidney damage. The history of kidney stones increases the risk.
  • Vasculitis (e.g., ANCA-associated vasculitis): This group of diseases can cause kidney inflammation and damage, leading to the observed urinary findings and edema. It's crucial to consider due to its potential for severe consequences if untreated.
  • Sepsis from a Urinary Tract Infection: If the patient's symptoms are due to an infection, there's a risk of sepsis, especially in the context of obstructive uropathy from a stone. Sepsis is a medical emergency.

• Rare Diagnoses

  • Amyloidosis: A condition where abnormal proteins (amyloid) accumulate in organs, potentially causing kidney damage and the observed symptoms. It's rare but should be considered in the differential diagnosis due to its unique treatment and prognosis.
  • Fabry Disease: A genetic disorder that can cause kidney damage among other systemic symptoms. It's rare and typically presents with more systemic symptoms, but could be considered in the differential, especially if other diagnoses are ruled out.