A Rare Cause of Arterial Hypertension in a Young Adult: The Role of a Large Renal Cyst

Abstract

Introduction: Arterial hypertension is a common and serious medical condition, often contributing to significant cardiovascular morbidity and mortality. While the majority of hypertension cases are classified as primary (essential), secondary hypertension, which results from identifiable causes, is also of clinical importance. Among the causes of secondary hypertension, renal abnormalities—particularly renal artery stenosis, chronic kidney disease, and renal cysts—are significant contributors. Although simple renal cysts are usually asymptomatic and benign, large cysts may cause renal compression, potentially leading to secondary hypertension through activation of the renin-angiotensin-aldosterone system (RAAS). Case Presentation: We present the case of a 44-year-old woman with a one-year history of poorly controlled hypertension. Despite initial pharmacological therapy and lifestyle modifications, her blood pressure remained above target levels. Imaging revealed a large, simple renal cyst measuring 14.7 × 12.7 × 9.9 cm in the left kidney, which significantly displaced renal parenchyma. Laboratory workup revealed elevated plasma renin levels, suggesting renin-mediated hypertension caused by the compression of renal tissue. Management and Outcome: The patient was started on a combination therapy of Amlodipine 5 mg (a calcium channel blocker) and Candesartan 16 mg (an angiotensin II receptor blocker), achieving partial control of blood pressure. Surgical intervention was not pursued at this stage, as the patient remained stable with no significant increase in cyst size on follow-up imaging. Close monitoring of blood pressure and periodic renal imaging were recommended for reassessment of the need for surgical intervention. Conclusion: This case highlights the role of large renal cysts as a rare but important cause of secondary hypertension. It underscores the importance of considering renal cysts in the differential diagnosis of resistant hypertension, especially when conventional pharmacologic therapy is inadequate. Long-term follow-up, including monitoring cyst size and blood pressure, is essential to optimize patient outcomes and guide further interventions if necessary.