Epithelial atypias associated with intrauterine contraceptive devices (IUD).

A total of 99 gynecologic smears with atypical cells from 74 patients wearing IUDs was reviewed. Endometrial and cervical tissues were examined. The cases were categorized into two groups, reparative and epithelial atypias. The latter category was further divided into three subgroups: squamous, columnar, and indeterminate type. The squamous atypia has classical features and is believed to be not significantly related to the IUD. Columnar atypia can strongly suggest cells shed from an adenocarcinoma. Indeterminate type of atypia is characterized by abnormal cells which can resemble cells shed from carcinoma in situ. Unlike the latter, the atypical cells from IUD are usually multinucleated, contain nucleoli, and are not associated with cells from severe cervical atypia. They are probably of endometrial origin.