[What should be done in the presence of isolated microscopic hematuria in man in the work environment?].

Microscopic haematuria was detected by the strip technique in 3.5% (normal: 1.8%) of 2100 men over 40 years of age, systematically examined at their place of work. Thirty-two agreed to undergo further investigations. Eight (25%) were found to have a urinary tract disease: kidney stones (2), prostatic adenoma (2), vesical diverticulum (1) and, notably, vesical tumour (2). Intravenous urography detected these abnormalities in 75% of the cases but missed the vesical tumours which were detected only at cystoscopy, urine cytology being also negative. The data obtained by cystoscopy were confirmed by vesical echography in 1 case. Thus, we believe that in the presence of even a single episode of microscopic haematuria in a man over 40, an intravenous urography should be performed. If the results are normal, and if the subject is a smoker or presents with an occupational or familial risk of cancer, this examination should be followed by cytology and vesical echography. If both are negative, then cystoscopy is necessary.