Limiting the use of atypical/inconclusive as a category in nongynecologic cytology specimens

'Atypical' has served as a descriptive term in cytology since the birth of the specialty by Dr Papanicolaou. This indeterminate diagnosis often results in repeat biopsies or additional tissue sampling and a needless delay in patient care if used inappropriately. Because of the definitional ambiguity of this term and the associated physician frustration, we have made a concerted effort at Methodist Hospital since 1995 to minimize the use of 'atypical' as a diagnostic category.

To evaluate whether the dissolution of the 'atypical' category has increased our cytologic-histologic discordance rate to more than the published reference range.

From March 3, 2006, through December 31, 2008, all nongynecologic cases with 'atypical/indeterminate' listed as the general diagnostic category were identified and retrieved from our laboratory data files. We then assessed the cytologic-histologic correlation rate during the corresponding time frame.

A total of 48 'atypical' cases (0.2%) from 19 347 nongynecologic specimens were identified. Of the 'atypical' cases, 52% (25 of 48) had intradepartmental consultation, 58% (28 of 48) had additional preparations examined, and 29% (14 of 48) documented limitations because of poor preservation. Our cytologic-histologic discrepancy rate for the period was 5.5% (214 of 3912 cases), with 89.3% (191 of 214 cases) resulting from sampling issues. On review of the small percentage of cytologic interpretative discrepancies, only one case was unhampered by less than 10% tumor cellularity or poor preservation.

Not using 'atypical' as a diagnostic category, unless defined by Bethesda guidelines, has not affected our cytologic-histologic correlation rate.