Human papillomavirus typing in patients with Papanicolaou smears showing squamous atypia

Three hundred sixty consecutive patients followed at the Massachusetts General Hospital Colposcopy Clinic had HPV typing performed from exfoliated cervical cells by a commercially available dot blot hybridization assay. This assay tests for three groups of HPV types: 6/11, 16/18, and 31/33/35. Of this group, 171 patients were referred because of a Papanicolaou (Pap) smear showing squamous atypia. Of the 171 patients referred for squamous atypia, 17 (10%) had histologic evidence of CIN. Thirty-three of the 171 (19%) had detectable HPV DNA, and 28 of the 33 had high-risk HPV types (16/18, 31/33/35). Of the 17 women with CIN, only 6 (35%) had high-risk types and 11 (65%) had no HPV DNA detected. Of the 28 women with atypia and high-risk HPV types, only 6 (21%) had CIN. This study demonstrates that commercially available HPV typing when used in patients with Pap smears showing squamous atypia is not clinically useful in identifying patients for colposcopic referral.