[Study of the renin-angiotensin system in 2 cases of Wilm's tumor with severe arterial hypertension].

Two children who presented with Wilm's tumour and severe hypertension are described. The hypertension, which was secondary to excessive renin secretion, regressed after unilateral nephrectomy. In one child the total quantity of renin in the tumour was high and the peripheral plasma renin was also increased. The latter was unaffected by posture or a low salt diet and on angiography there was no compression of the renal arteries. Electron microscopy of the tumour cells showed numerous intra-cytoplasmic granules. In the other child the peripheral renin was only moderated elevated and could be stimulated by changes in posture or a low salt diet. Angiography demonstrated a large tumour that was compressing the renal artery on that side. No renin was detected in the tumour. In this child the inappropriate secretion of renin was probably due to renal parenchyma close to the tumour causing reno-vascular hypertension. The anti-hypertensive effect of propranolol given pre-operatively was excellent.