Colposcopic accuracy in the diagnosis of microinvasive and occult invasive carcinoma of the cervix.

One hundred eighty patients with microinvasive and occult invasive squamous cell carcinoma of the cervix who were examined by colposcopy during a ten-year period are reviewed. Forty-two percent of patients with microinvasive carcinoma and 28% of patients with occult invasive carcinoma had an unsatisfactory colposcopic examination. Colposcopy led to the correct management in 90% of patients with occult invasive cancer and in 84% of patients with microinvasive carcinoma. Colposcopy appeared to be less sensitive in detecting microinvasive lesions than in detecting occult carcinoma. Two-thirds of the errors made were colposcopist-related, either failure of interpretation or protocol violation. A small but definite group of patients will have lesions whose colposcopic appearance is not sufficiently distinct or characteristic to permit a diagnosis of early invasion.