Atypical squamous cells. A case-series study of the association between papanicolaou smear results and human papillomavirus DNA genotype.

Thirty women with "atypical" squamous cells but not cervical intraepithelial neoplasia (CIN) on their Papanicolaou smears were tested for the presence of human papillomavirus (HPV) with the Southern blot hybridization technique. The Papanicolaou smears were reviewed for the presence of atypical squamous cells according to Patten's criteria. Comparison groups consisted of 30 patients with normal, 29 patients with CIN I and 24 patients with CIN II Papanicolaou smears. Ten of the 30 women (33%) with atypical cells on Papanicolaou smears were positive for HPV DNA as compared to 17% with normal and 59% with CIN I or II Papanicolaou smears. HPV 16 was present in 70-80% of the HPV DNA-positive patients in each Papanicolaou smear group. Concurrent CIN was also identified on colposcopically directed biopsies in 27% of the patients with squamous atypia. Patients with atypical squamous cells on Papanicolaou smears had coexisting HPV infection and CIN in about one-third of the cases. Colposcopy and further follow-up are recommended for such patients.