Urinary cytologic examinations of laboratory workers. Useful medical surveillance tool or clinician's nightmare?

An apparent excess of abnormal urine cytological findings in crime laboratory workers exposed to potentially carcinogenic aromatic amines was investigated by a cross-sectional epidemiologic study comparing these workers with an unexposed control group. The prevalence of atypical findings in the laboratory workers exceeded that in the control group; however, the results were not statistically significant. A number of serious problems were identified including a high prevalence of inflammatory changes (25% to 26%) and a moderately high percentage of atypical changes (2.5% to 5.4%) in the control population, failure to detect (on urological workup) evidence of neoplastic disease of the urinary tract in any of the laboratory workers whose urine examinations were cytologically interpreted as either atypical or neoplastic cells, and difficulty in determining proper referral criteria for urological workup.