Inadequate cervical smears: results of an educational slide exchange scheme

Fifty-six slides, predominantly inadequate and of varying difficulty, were circulated to 12 laboratories as an educationally based slide exchange sche me. Three slides failed to achieve an agreed majority consensus opinion. Se venty percent of participants agreed with the consensus opinion in 80% of s lides. Of the slides originally reported as inadequate, the consensus diagn osis was inadequate in 78%, negative in 12% and abnormal in 10%. The latter included two cases of high-grade dyskaryosis, There was good agreement for the two most frequent causes of inadequacy in submitted slides (obscured a nd poor cellularity). There was poor consistency in reporting the presence or absence of endocervical and immature squamous metaplastic cells, to an e xtent that questions their use in the assessment of smear adequacy. Three i nadequate slides on consensus opinion were associated with subsequent cervi cal intraepithelial neoplasia (grade III) or invasive squamous cell carcino ma. In the latter case, the slide had originally been reported as negative by the submitting laboratory.