Is large loop excision of the transformation zone (LLETZ) more accurate than colposcopically directed punch biopsy in the diagnosis of cervical intraepithelial neoplasia?

In 100 women with suspected cervical intraepithelial neoplasia (CIN) attending the colposcopy clinic the histological diagnoses made from excision biopsies taken by large loop excision of the transformation zone (LLETZ) were compared with those from colposcopically directed punch biopsies taken concurrently. One unsuspected microinvasive tumour was found and the diagnosis made by LLETZ was significantly worse than that made by punch biopsy in 24 cases (24%: 95% CI 15.6 to 32.4%). LLETZ improves the accuracy of diagnosis of CIN.