Hypertension and a missing kidney.

Standard initial assessment via ultrasound of a 4-year-old girl with hypertension revealed the absence of one kidney. Instead of cross-sectional imaging of the retroperitoneal space, a functional (nuclear) study was performed. This revealed a malformed kidney within the chest. Though systemic levels of renin and aldosterone were not elevated, removal of the malformed kidney normalized the blood pressure. The presence of prominent smooth muscle nodules surrounding the arteries was seen in the malformed kidney. Initial attempts to avert surgery by pharmacologically reducing blood flow to the malformed kidney were unsuccessful. The review of the literature offers little evidence to support such a strategy.