High renin hypertension associated with renal cortical cyst.

A fifty-seven-year-old patient with a five to one elevation of right renal vein plasma renin activity associated with a large, simple cortical cyst of the right lower pole is presented. Marsupialization of the cyst was associated with improvement in the patient's hypertension and the finding of bilaterally equal renal vein renin activity three months postoperatively. Possible mechanisms for hypertension are discussed in context of the experimental models of Goldblatt and Page in such lesions as cortical cysts of large size causing hydronephrosis, vascular stretching, or renal parenchymal compression.