[The place of kidney biopsies in the diagnosis of isolated hematuria].

Twenty-six patients with idiopathic hematuria, i.e. with normal intravenous pyelography, without arterial hypertension, renal failure or significant proteinuria, underwent renal biopsy in our institution between 1973 and 1981. Segmental proliferative endocapillary glomerulonephritis was diagnosed in 13 cases; in the other 13 patients the renal tissue was either normal (6) or presented only minor lesions of the mesangium (5) or interstitial tissue (2). Twenty-two patients underwent a follow-up examination after a mean of 51 months (range 12-120). The hematuria had disappeared in half of them and no patients had developed hypertension or renal failure. These results suggest that in cases of idiopathic hematuria renal biopsy is not indicated for prognostic or therapeutic reasons, though in some cases it may avoid repeated and potentially dangerous investigations.