Malignant hypertension due to a renin-secreting renal cell carcinoma--an ultrastructural and immunocytochemical study.

This is a case report of a 14-year-old girl who presented with malignant hypertension. She had high plasma levels of both active and inactive renin and investigation revealed a renal tumour. The tumour, a renal cell carcinoma, was removed by nephrectomy following which the blood pressure and the plasma renin levels fell to normal. An immunocytochemical study using an antibody to pure human renin showed no detectable renin in the kidney but the tumour contained a population of granular cells which showed strong positive staining for immunoreactive renin. We present the clinical, biochemical, histological, immunocytochemical and ultrastructural features of this case as evidence that this was a renin-secreting renal cell carcinoma.