A comparative study of the assessment of cervical intraepithelial neoplasia in women having large loop excision of the transformation zone.

Findings on Papanicolaou (Pap) smear and colposcopically directed punch biopsy show discrepancies when compared with findings on loop excision specimens and this situation creates management problems. We performed a comparative assessment of cervical intraepithelial neoplasia (CIN) in 100 consecutive women who had large loop excision of the transformation zone (LLETZ) with a view to developing a local protocol that would be safe, avoid delay and minimise over-treatment. Agreement between Pap smear and LLETZ was 62% with 21% overcall and 17% undercall at Pap smear; there was no significant correlation (Spearman's rank correlation coefficient 0.17 P > 0.05). The agreement between punch biopsy and LLETZ was 61% with 25% overcall and 15% undercall at punch biopsy; there was a slight agreement over chance (kappa=0.20) and there was a weak but significant correlation (Spearman's rank correlation coefficient=0.26; P = 0.047). Colposcopic impression of 'highly abnormal'lesions agreed with high grade lesions on LLETZ in 83% of cases. The problem of undercall suggests that defaulters with apparent low grade dyskaryosis need to be pursued to colposcopy as vigorously as defaulters with high grade dyskaryosis. The lack of significant correlation between cervical cytology and LLETZ finding suggests that the smear-to-colposcopy waiting interval should not be strictly based on the degree of dyskaryosis.