INTEROBSERVER VARIABILITY OF CERVICAL SMEARS WITH SQUAMOUS-CELL ABNORMALITIES - A PHILADELPHIA STUDY

The reproducibility of reporting squamous lesions by the Bethesda Syst em (TBS) was evaluated by distributing 20 slides to be classified amon g 5 panelists considered experts in the field of cytopathology. Four c ases were chosen for their classic morphology and the remainder were f oreseen to produce possible discrepancies within one diagnostic catego ry. For 7/20 (35%) cases there was unanimous agreement. Participants d isagreed within one category of magnitude for seven (35%) cases. In si x (30%) cases there was a range of more than one category disagreement . However, additional written comments modifying TBS diagnoses often d iminished the clinical significance of these discrepancies. We conclud e that despite the important role of TBS in standardization of Pap sme ar reports, a great degree of subjectivity exists in classifying squam ous abnormalities without ''classic'' morphology. The lack of reproduc ibility should be taken into account in cytology proficiency testing. (C) 1994 Wiley-Liss, Inc.