A distinctive abnormality in the appearance of the cells of the skin of the cervix, in which some of the nuclei are surrounded by tiny “halos.”

Most commonly, these changes occur in the presence of HPV (Human Papilloma Virus) but occasionally are associated with more serious problems such a cervical dysplasia or even early malignancy.

Patients demonstrating koilocytosis who previously had normal Paps are ideally evaluated with colposcopy and cervical biopsies to determine the source of the koilocytes, although such evaluation can usually safely wait for weeks to a few months if necessary because of operational requirements.