Colposcopic evaluation of patients with abnormal cervical cytology.

Because of suspicious or abnormal smears, 620 patients were referred to the Colposcopy Clinic of the British Columbia Cancer Institute between 1st March 1973 and 31st December 1974; it was possible to make a colposcopic examination in 549 of these patients (88.5 per cent). The colposcopic impression was within one histological grade of a colposcopically-directed biopsy in 476 patients (86 per cent). There were 221 patients who had a cone biopsy after a colposcopically-directed biopsy and in 192 of these (87 per cent) the two biopsies were within one histological grade of each other; but there were two patients with occult invasive carcinoma in a cone biopsy and only carcinoma in situ in a directed biopsy. In the same group of 221 patients the colposcopic evaluation and final diagnosis (the most advanced histological lesion seen in biopsy) agreed in all but seven patients.