Aim: To investigate the oncologically safe limits of excision in large loop excision of the transformation zone (LLETZ) conisation performed for cervical pathology.
Patients and methods: A retrospective study conducted at the Colposcopy Unit in a University Hospital setting. Three hundred and sixty-one cases of LLETZ conisation were conducted in a 2-year period. Data concerning age, cone dimensions, lesion types and excision margins were recorded.
Results: The mean age of women was 36.7 years, with 181 (50.5%) low-grade squamous intraepithelial lesion cases, 166 (45.7%) high-grade squamous intraepithelial lesion, and 14 (3.8%) with stage-IA1 cervical carcinoma. Mean conisation depth and cone volume were 10.9 mm and 2.2 ml, respectively. Incomplete removal of lesions occurred in 25% of women and correlated to severity of cervical intraepithelial neoplasia and conisation depth. The higher the grade of the lesion, the greater the percentage of residual disease. Conisation depth exceeding 10 mm, in our cohort, led to significantly less residual disease.
Conclusion: Results indicate that a conisation depth of <10 mm may be a risk factor predicting positive resection margins, while cone volume is an inappropriate clinical marker.