ASC-H RECONCILIATION: LIMITATIONS OF HISTOCYTOLOGIC CORRELATION AND IMPORTANCE OF REPRESENTATIVE BIOPSY

Charles J Bechert, MD, R Nawgiri, M.D., V Schnadig, M.D.

Department of Pathology, UTMB

Background: An interpretation of ASC-H on a cervical Pap test represents a differential that includes high grade squamous intraepithelial lesion (HGSIL), immature squamous metaplasia, cervicitis with regenerative changes, and lower uterine cell sampling. Colposcopy and directed biopsy are necessary to exclude a high grade lesion. If the biopsy diagnosis does not correlate with cytology, review and reconciliation of the pathology is warranted. Reconciliation requires review of Pap and scrutinization of biopsy for changes, benign or neoplastic, that are representative of or could explain abnormal Pap cytology. Design: 35 cases interpreted as ASC-H were evaluated retrospectively in conjunction with cervical biopsies. Selection criteria included cases of ASC-H on Pap (Surepath®), that also had biopsies performed concurrently or within prior 6 months. All cases were re-examined microscopically and reviewed to reconcile any discrepancies between Pap and biopsy. Data gathered included adequacy of biopsy, diagnostic classification, discrepancies, and if reconciliation between Pap cytology and biopsy was possible. Biopsies were considered adequate only if they contained changes that could explain Pap findings. Results: Of 35 ASC-H cases, 9 cases (26%) had high grade lesions (CIN II / CIN III) on biopsy that correlated with cytology. The remaining 26 cases (74%) required review for reconciliation of Pap-biopsy discrepancy. After review, 15 cases (58%) remained unreconciled because biopsies did not represent lesion sampled on Pap. In 50% of reviewed cases, we obtained additional diagnostic information such as presence of squamous metaplasia, ulcerative cervicitis, and focal high grade lesions. This additional diagnostic information enabled reconciliation of 11 reviewed cases (42%). Conclusion: A majority of ASC-H cases could not be reconciled for lack of representative biopsies. Skillfully performed colposcopy is essential to obtaining representative biopsies. When Pap-biopsy discrepancy existed, review with correlation proved imperative, often yielding additional, valuable diagnostic information. Benign changes that could explain abnormal Pap cytology were often omitted from surgical pathology reports. Upon review, identification of benign changes or focal high grade lesions enabled reconciliation of Pap with biopsy. (Supported by the UTMB Department of Pathology).