Renin in renal cell carcinoma--an immunocytochemical study using an antibody to pure human renin

We have studied a series of 19 primary renal cell carcinomas using an antibody to pure human renin and the indirect PAP technique. Seven tumours contained immunoreactive renin. No renin was identified in seven cases of metastatic tumour within the kidney, but immunoreactive renin was present in two out of seven metastatic renal cell carcinomas in other organs. None of the subjects had clinical, biochemical or histological evidence of excess renin secretion. We suggest that renal cell carcinoma may commonly secrete renin and that the hormone may be biologically inactive.