INTEROBSERVER VARIABILITY IN THE CLASSIFICATION OF PROLIFERATIVE BREAST-LESIONS BY FINE-NEEDLE ASPIRATION - RESULTS OF THE PAPANICOLAOU SOCIETY OF CYTOPATHOLOGY STUDY

This study evaluates the applicability of the published cytologic crit eria ill the categorization of proliferative breast lesions by assessi ng the diagnostic accuracy and interobserver reproducibility of a pane l of experts. Twelve breast fine-needle aspiration (FNA) specimens of biopsy-proven nonproliferative breast lesion (NPL) (1 case), prolifera tive lesions without atypia (PL) (7 cases), proliferative lesion with atypia (PLA) (1 case), and low-nuclear grade ductal carcinoma in situ (DCIS) (3 eases) were selected Sir FNAs were Papanicolaou (PAP) mid 6 were Diff-Quik-stained (DQ). Six expert cytopathologists classified th e smears using a summary of published criteria as a guideline. All 6 p articipants rendered the same cytologic diagnosis in 2/12 (16%) cases. The agreement among the 6 raters was low (Kappa = 0.35). Cytohistolog ic correlation was achieved in 26/72 (36%) FNA diagnoses. The correlat ion of the PAP-stained cases was better than the De: 17/36 (47%) PAP a nn 9/36 (25%) DQ correlated Improving the correlation was achieved by amalgamation of NPL mid PL into ''low risk'' and PLA and DCIS into ''h igh risk'' categories: 47/72 (65%) FNA diagnoses then cot-related with histology [29/36 (81%) PAP and 18/36 (50%) DQ]. We conclude that the cytologic criteria of proliferative breast lesions need to be further defined and assessed. Consideration should be given to minimizing the number of diagnostic categories and adopting a terminology that has a direct effect oil patient management. (C) 1998 Wiley-Liss, Inc.