Differential Diagnosis for Persistent High BP and Asymmetry in Kidney Sizes

• Single most likely diagnosis
  • A. Renal artery stenosis: This condition is a common cause of secondary hypertension, especially in elderly patients, and can lead to asymmetry in kidney sizes due to decreased blood flow to the affected kidney, resulting in atrophy. The presence of multiple anti-hypertensive medications without adequate blood pressure control raises suspicion for a secondary cause of hypertension.
• Other Likely diagnoses
  • B. Adult Polycystic Kidney Disease (PCK): While this condition can cause asymmetry in kidney sizes due to the formation of cysts, it typically presents with a family history and other systemic manifestations. However, it remains a consideration, especially if there's a known family history or other suggestive findings.
  • C. Pheochromocytoma induced HTN: Although less common, pheochromocytoma can cause resistant hypertension. However, it would not directly cause asymmetry in kidney sizes unless it led to a secondary condition affecting kidney size, such as renal artery stenosis due to a tumor compressing the renal artery.
• Do Not Miss diagnoses
  • Renal vein thrombosis: This condition can cause acute kidney injury and hypertension but is less likely to present with long-standing hypertension and asymmetry in kidney sizes without other acute symptoms. However, it's crucial to consider due to its potential for severe consequences if missed.
  • Aortic dissection involving the renal arteries: Although rare, this is a life-threatening condition that could lead to unequal kidney perfusion and size. It's essential to rule out, especially in the context of resistant hypertension and asymmetrical kidney sizes.
• Rare diagnoses
  • Fibromuscular dysplasia: A rare cause of renal artery stenosis, more commonly seen in younger females, but could be considered in the differential diagnosis of an elderly patient with resistant hypertension and asymmetrical kidney sizes.
  • Other vascular abnormalities: Such as arteriovenous malformations or rare genetic disorders affecting the renal vasculature, which could potentially cause the described symptoms but are less likely.