Subdividing atypical glandular cells of undetermined significance according to the Australian modified Bethesda system - Analysis of outcomes

BACKGROUND. The Australian modification of the Bethesda system (TBS) for re porting endocervical cellular abnormalities differs from TBS in having a "h igh grade" category for prediction of adenocarcinoma in situ (AIS), an "inc onclusive" category requiring that AIS be excluded (AISEX), and a "low grad e" category (Enatyp) for when only minor changes are seen in endocervical c ells. METHODS. From subsequent follow-up, the authors evaluated the proportion of histologically confirmed high grade lesions (squamous, glandular, or endom etrial) in each cytologic reporting category, for cases in which no concurr ent squamous abnormality was also predicted. RESULTS. From information was available for 95.9% of 172 AIS predictions, 8 1.5% of 119 AISEX predictions, and 89.0% of 237 reports of Enatyp. The hist ologic positive predictive values for high grade lesions were 95.7% for AIS . 71.1% for AISEX, and 7.1% for Enatyp. In the first 2 categories, a minori ty of lesions proved to be purely squamous (3.8% for AIS and 33.3% for AISE X), whereas in the Enatyp category 87.0% were squamous only. CONCLUSIONS. Compared with TBS, the Australian terminology for reporting of endocervical abnormalities better reflects the risk of underlying high gra de abnormalities and may result in more appropriate management recommendati ons. For Enatyp reports, which constitute over 85% of reported endocervical abnormalities, repeat cytology should be considered appropriate management . However, cone biopsy should be the investigative method of choice for wom en with reports of AIS and AISEX. (C) 2000 American Cancer Society.