Objective: To estimate the disagreement between the histologic reports at colposcopically directed punch biopsy of the cervix and subsequent loop excision of the transformation zone, and to assess the indications for loop excision in current practice.
Methods: The histologic diagnoses from loop electrosurgical excision procedures and concurrent colposcopically directed punch biopsies were compared in 337 consecutive women undergoing loop excision in a 5-year period.
Results: Disagreement between punch biopsy and loop excision was recorded in 190 cases (56.4%). The undercall and overcall rates for punch biopsy were 14 and 42.4%, respectively. Undercall at punch biopsy occurred in 24 of 46 cases of cervical intraepithelial neoplasia (CIN) III and in one microinvasive cancer diagnosed at loop excision, and disagreement was within one grade of CIN in 16 cases.
Conclusions: Loop electrosurgical excision allows further and more accurate histologic examination of the transformation zone and should be the standard assessment procedure in all cases of CIN II detected at punch biopsy and whenever cytology or colposcopy suggests the risk of punch biopsy undercall. Immediate treatment by local destruction should not be performed, to avoid underestimation of the severity of the lesion.