Management of low grade lesions: follow-up or treat?

CIN has arbitrarily been divided into three categories (1, 2 and 3) and recently a revised classification of high and low grade lesions has been suggested. Whatever classification is used, there appears to be a high level of inter- and intraobserver variability in diagnosing the grade of CIN, particularly at the minor end of the spectrum. Punch biopsy diagnoses are undoubtedly associated with both underdiagnosis and overdiagnosis of lesions, depending on the size of the lesion and the site of the worst colposcopic abnormality chosen for such investigation. The consensus is that high grade lesions should be treated once diagnosed. The dilemma of treatment of low grade lesions is more vexed and is hampered by the lack of reliable data on progression, persistence and regression rates. Local circumstances must be taken into consideration and if surveillance is not possible, then all cases of CIN should be treated. However, if women are prepared to undergo surveillance, this may be offered with certain safeguards. At present we would suggest treatment of those being observed if they continue to have an abnormality persisting for 2 years or if the lesion worsens in grade or size. It may be that the size of the lesion is of major importance in its progressive potential. The overall impact of screening programmes must be to do more good to the population than harm and the optimal management of low grade lesions is uncertain in this context.