Humidity Conditions Involved in the Formation of Cornflake Artifacts in Papanicolaou Stains

Cornflake artifacts that appear in cervical cytology are formed by a poorly dehydrated series of Papanicolaou (Pap) stains and dried before mounting. This study focused on the humidity conditions during Pap staining to investigate the cause of the appearance of cornflake artifacts in Pap smears. One SurePath™ liquid-based cytology cell specimen, diagnosed as negative for intraepithelial lesions or malignancy and human papillomavirus using the uniplex E6/E7 PCR method, was used. The draft humidity was adjusted to 30%, 50%, 70%, and 80%. Subsequently, poorly dehydrated series of Pap staining according to the method was performed. After the last xylene immersion, smears that were not dried and dried after 1, 3, and 5 min were mounted. Cornflake artifacts were not observed in smears that had not been dried and dried for 1 min under any humidity condition. In the smear dried for 3 min before mounting, cornflake artifacts were observed at only 80% humidity, and the ratio of cornflake artifacts to normal squamous cells was 0.04 corn/nsc. The ratios when smears were dried for 5 min before mounting at 30%, 50%, 70%, and 80% humidity were 6.44, 6.80, 6.53, and 1.46 corn/nsc, respectively. This study revealed that the appearance of cornflake artifacts in Pap stains under poor dehydration conditions is related to high humidity.