Koilocytosis in neoplasia of the urinary bladder.

Koilocytosis is commonly regarded as indicative of human papilloma virus infection in the uterine cervix. In 1987 morphologically similar changes were reported in bladder tumours. This is confirmed in the present study, the incidence here being 65%. In addition the incidence of koilocytic change was shown here to increase from non-infiltrative WHO grade I to infiltrative WHO II lesions, and to be more common in bladder lesions in women with cervical koilocytosis. The latter is in keeping with our previous report that the incidence of koilocytosis in the cervix of patients with bladder neoplasia is higher than expected in the general population, adding support to the hypothesis that both lesions may be virus-related.