Is microscopic haematuria a urological emergency?

Objective To determine the prevalence of urological pathology in a retrospective and prospective study of patients with microscopic haematuria attending a haematuria clinic. Patients and methods Between January 1998 and May 2001, 781 patients attended the haematuria clinic; of these, 368 (47%; median age 60 years, range 18-90) had a history of microscopic haematuria, as detected by urine dipstick testing. These patients were investigated by urine culture and cytology, renal ultrasonography, intravenous urography (IVU), flexible cystoscopy, urea and electrolyte analysis, and assay of prostate specific antigen (PSA) where appropriate. Results Urine cytology showed no malignant cells in any patient with a history of microscopic haematuria. In 143 patients (39%), urine cytology showed no red blood cells and all other investigations were normal. Of the remaining 225 patients, IVU showed a tumour in one (bladder), renal stones in 15 and an enlarged prostate in two. Renal ultrasonography detected no additional pathology. Urine analysis showed one urinary tract infection. Flexible cystoscopy detected five patients with a bladder tumour (all G1pTa), two urethral strictures, five bladder stones and enlarged prostates, six enlarged prostates only, and nine red patches in the bladder, showing one patient with carcinoma in situ. No PSA levels were suggestive of prostate cancer. Conclusion Patients with dipstick-positive haematuria should be re-assessed by urine microscopy before referral. As only 1.4% of patients had a malignant pathology (all noninvasive), microscopic haematuria should be regarded as a separate entity from macroscopic haematuria, and such patients do not need to be referred urgently.