Comparison of the overall dimensions of large loop excision specimens of the cervix with the dimensions on histology

Abstract

This study was carried out to establish whether the macroscopic/gross dimensions of a cone biopsy or large loop excision of the transformation zone specimen (LLETZ) were a reliable reflection of the microscopic measurements and whether any of these dimensions could be used to reliably predict whether the deep lateral stromal margin of the specimen was involved. This is because the transection of cervical crypts involved by cervical intraepithelial neoplasia is likely if the amount of tissue removed is said to be less than 4.8 mm when measured on the histological specimen. Prior to sectioning using the standard method, the gross external dimensions of the specimens were recorded. These were compared with the length of the ectocervical surface, endocervical canal, and the deep stromal measurement, defined as the maximum perpendicular distance between the stromal resection edge at the deep lateral limit and the epithelial covered surface, on the microscopic slide. Although 94.6 (91.4-96.7)% of the specimens had a deep stromal measurement in excess of 4.8 mm, 21.1% of these had involved deep stromal margins while 27.3 (22.6-33)% of those with a stromal measurement less than 4.8 mm had involved deep margins (p = 0.9144). None of the gross dimensions correlated with the microscopic measurement of stromal depth. The current audit figures indicate that it is not possible to predict whether sufficient tissue has been removed simply from assessing the overall gross dimensions of the LLETZ specimen.