An ultrastructural and immunocytochemical study of a renal carcinoma secreting inactive renin

This is a case report of a renal carcinoma which was secreting inactive renin. Using an antibody to human renin and the indirect immunoperoxidase technique, the renin-containing cells were localised within the tumour. These were found to be small granular cells situated in a perivascular position. The histological immunocytochemical and ultrastructural features of these cells are described.