DIAGNOSTIC-ACCURACY OF CYTOLOGY AND COLPOSCOPY IN CERVICAL SQUAMOUS INTRAEPITHELIAL LESIONS

Objective. To evaluate the diagnostic accuracy of cytology and colposc opy in women with an abnormal cervical smear using histology as the 'g old standard'. Design. Survey of consecutively referred women with abn ormal smear. Setting. The out-patient colposcopical clinic of Herning Hospital, Denmark. Patients. 813 women with a median age of 29.0 years (range 15-71 years) with their first abnormal smear. Results. For det ecting cervical high-grade lesions (HGL) the sensitivity of cytology w as 41% (36-47%), of colposcopy 67% (62-72%) and in combination 75% (70 -80%), so at least 25% of HGL were underestimated. Colposcopy underest imated more CIN-2 than CIN-3 lesions and more small lesions and lesion s in smaller transformation zones. Cytology underestimated more CIN-2 lesions but equal numbers of small and large lesions and transformatio n zones. Conclusions. Colposcopy was a better tool for diagnosing HGL than cytology, but even in combination too many HGL were missed. All w omen with abnormal cytology should therefore have colposcopical and hi stological investigation and prospective studies of the natural histor y of cervical squamous lesions should include histological evidence.