Differential Diagnosis for a 71-year-old Male with Elevated Urea and Creatinine

Single Most Likely Diagnosis

• Chronic Kidney Disease (CKD): The presence of bilateral exophytic renal cysts and right-sided focal scarring, along with elevated urea (54.7) and creatinine (1.98) levels, strongly suggests CKD. The renal cysts and scarring can lead to a decline in kidney function, which is consistent with the laboratory findings.

Other Likely Diagnoses

• Autosomal Dominant Polycystic Kidney Disease (ADPKD): Given the presence of bilateral exophytic renal cysts, ADPKD is a possible diagnosis. This condition often leads to CKD and can present with similar laboratory and imaging findings.
• Diabetic Nephropathy: Although not directly mentioned, the patient's age and the presence of kidney damage (focal scarring) could suggest diabetic nephropathy, especially if the patient has a history of diabetes mellitus.
• Hypertensive Nephrosclerosis: Chronic hypertension can lead to kidney damage, including scarring and a decline in function, which could explain the patient's presentation.

Do Not Miss Diagnoses

• Urinary Tract Obstruction: This condition can cause acute kidney injury or exacerbate existing CKD. It's crucial to rule out obstruction, especially with the presence of renal cysts, which could potentially obstruct the urinary tract.
• Renal Cell Carcinoma: Although less likely, the presence of exophytic renal cysts and focal scarring could, in rare cases, be associated with renal cell carcinoma. This diagnosis would have significant implications for treatment and prognosis.
• Vasculitis (e.g., ANCA-associated vasculitis): Certain types of vasculitis can affect the kidneys and present with rapidly progressive glomerulonephritis or CKD. Although less common, missing this diagnosis could have severe consequences.

Rare Diagnoses

• Alport Syndrome: A genetic disorder affecting the type IV collagen in the kidneys, leading to CKD. It's less likely given the patient's age and the absence of other typical findings like hearing loss.
• Fabry Disease: A genetic disorder that can lead to CKD among other systemic manifestations. It's rare and typically presents earlier in life, but late-onset forms can occur.
• Amyloidosis: A condition where abnormal proteins deposit in the kidneys, leading to CKD. It's rare and would typically be associated with other systemic symptoms or findings.