[False positive urinary cytology. Diagnostic and prognostic value in the detection and surveillance of urothelial tumors. Apropos of 57 false positive cases in a series of 1000 cytologies]. / Les cytologies urinaires "faussement positives". Valeur diagnostique et pronostique dans le dépistage et la surveillance des tumeurs urothéliales. A propos de 57 cas de "faux positif" sur une série de 1,000 cytologies.

Out of 1,000 optical cytological urine tests carried out over a period of two years, 84 isolated cases were "positive" and alerted 57 patients. These cases are analyzed by the authors with a follow-up period of 48 to 72 months: among those patients already under supervision for urothelial tumours, 40.4% showed urothelial recurrence of which 70%, that did not appear to carry a worse prognosis, were detected in the first twelve months. Since these patients usually underwent annual endoscopic examination, this meant that for 20% (i.e. 4.15% of the group under supervision) the diagnosis of recurrence could be made at least 6 months earlier. This alone is a justification for cytological examination which does not involve any complications but merely entails increased cystoscopic and biopsy tests. On the other hand, there appear to be no grounds to advocate mass "screening" except in populations with warning symptomatology (especially haematuria) for which the ratio of positive findings in this series was 2.3/1,000. The future development of automatic apparatus for cytological tests should obviate the significant personal factor involved in cytological examinations, as shown by a review of the literature.