WHEN IT comes to the management of women with abnormal Papanicolau (Pap) smears, clinicians are likely to respond to questions about ASCUS—atypical squamous cells of undetermined significance—with a simple but telling phrase: "Don't ask us."
While the term 'ASCUS' is used to define Pap smears containing squamous cells of abnormal appearance that do not meet the criteria for defined epithelial abnormalities, on a practical level the diagnosis represents an "I-don't-know" category, noted Ralph M. Richart, MD, in a presentation at the annual meeting of the American College of Obstetricians and Gynecologists. Consequently, an ASCUS diagnosis presents vexing problems for cytopathologists, obstetricians, and gynecologists.
The ASCUS category is filled with a variety of patients: those with low-grade squamous intraepithelial lesions (LSIL), high-grade squamous epithelial lesions, and hidden invasive cancers. "ASCUS has become kind of a wastebasket, like Class 2 smears were years ago," says Raymond H. Kaufman, MD, a professor in