Frozen-section evaluation of cervical adenocarcinoma at time of radical trachelectomy: pathologic pitfalls and the application of an objective scoring system.

OBJECTIVE: To analyze the incidence of diagnostic discrepancy between frozen-section and final diagnosis of the endocervical margin at time of radical trachelectomy and to apply an objective scoring system to non-invasive endocervical glandular atypia to determine its utility in distinguishing benign from malignant lesions.
METHODS: Histologic slides from 19 cases of radical trachelectomy performed for invasive endocervical adenocarcinoma were evaluated for correlation between the frozen and permanent sections of the endocervical margin. An objective scoring system for grading non-invasive endocervical glandular lesions proposed by Ioffe et al. was also applied to the frozen and permanent section slides and compared to the final diagnosis.
RESULTS: There was 84% concordance between the frozen-section and final diagnosis using histology alone, vs. 95% concordance using the Ioffe scoring system. One trachelectomy was converted to completion hysterectomy for what was presumed to be adenocarcinoma in situ at the margin, which in retrospect, was a benign lesion and was correctly classified using the Ioffe system. Most of the discrepancies were due to misinterpretation of tubal metaplasia, tubo-endometrioid metaplasia, and atypical tubal metaplasia as adenocarcinoma in situ.
CONCLUSION: Benign mimics of endocervical adenocarcinoma in situ can be difficult to distinguish from malignant lesions, especially during frozen-section evaluation of the trachelectomy. Correctly diagnosing the margin status intraoperatively has great clinical impact and the application of an objective scoring system, like that proposed by Ioffe et al., can increase diagnostic accuracy when applied to frozen-section slides and better correlates with final diagnosis when compared to histology alone.