Conned by Conn’s: The Manifestation of Conn’s Syndrome Post-renal Transplant in a Patient with Polycystic Kidney Disease

We present the case of a 66-year-old African-American male with end-stage renal disease (ESRD) secondary to polycystic kidney disease (PCKD), with well-controlled hypertension. He was placed on peritoneal dialysis for two years before successfully undergoing a cadaveric renal transplant. There was an immediate graft function with no relevant postoperative complications. On regular follow-ups two months later, the patient now presents with worsening control of hypertension despite an increase in anti-hypertensive medications. Common causes of new-onset hypertension, such as renal artery stenosis, anti-calcineurin therapy, and allograft injury, were excluded. The patient’s biochemistry revealed the presence of hypokalemia, which was absent in previous reports. In light of this, plasma aldosterone and renin levels were sent and were found to be elevated: aldosterone: 50.4 ng/dL, renin: 0.4 ng/dL, aldosterone-renin Ratio (ARR): 126. In retrospect, a routine CT (computed tomography) scan performed in 2017 revealed an adrenal adenoma of 17 x 13 mm, which was diagnosed as an incidental finding at that time. A repeat CT scan was performed and showed no change in the size of the adenoma. In view of the new symptoms, the patient was started on spironolactone with little to no improvement in blood pressure and potassium levels. We present a case of Conn's syndrome in a patient with PCKD manifesting only after a renal transplant.