[Segmental renal hypoplasia of an adult originating from pseudo-tumor hyperreninism].

A 38 year-old man was admitted for severe hypertension with hypokalemia. Blood pressure was 180-120 mmHg, funduscopic examination revealed grade II retinopathy and left ventricular hypertrophy was present. Laboratory data disclosed: natremia = 140 mmol/ml, kalemia = 2.8 mmol/l, chloride = 105 mmol/l, bicarbonate = 30 mmol/l, creatinine clearance = 100 ml/mn, natriuresis = 140 mmol/day, kaliuresis = 80 mmol/day. Intravenous pyelography was normal. Angiography revealed a defect in the mid third of the right kidney without arterial abnormalities. Study of renin angiotensin aldosterone system showed: plasma renin activity: peripheric blood = 36 ng/ml/h (normal range I to 2), right renal vein = 30 ng/ml/h. Left renal vein = 18 ng/ml/h, inferior cava vein = 19 ng/ml/h. Plasma aldosterone level = 86 ng/100 ml (normal range 10 to 15). Captopril acute administration was followed by a fall of BP to 70-50 mmHg at 2 hours. Right nephrectomy was performed and revealed an ischemic retracted cortical area without necrosis nor tumoral aspect. The day after BP was 140/80 mmHg. Eight days after, kaliemia was 4.2 mmol/l, PRA was 0.5 ng/ml/h. Light microscopy showed that affected area was sharply delimited from surrounding normal tissue. In this area, glomeruli were present and seemed more numerous as usual; interstitial fibrosis and infiltrates of inflammatory cells were also noted. The main fact was tortuosities of intralobular arteries, thickened, with intimal proliferation. There was a pelvic recess near this cortical tissue. Immunofluorescence findings: antirenin serum fixed on JGA but also on interlobular arterial walls and on peritubular interstitium.(ABSTRACT TRUNCATED AT 250 WORDS)