Atypia is a histopathologic term used to describe a structural abnormality in a cell, indicating atypical cells. Atypia can be caused by an infection or irritation, and if diagnosed in a Pap smear, it is more likely to be precancerous. Atypia is not necessarily cancerous, and many factors can make normal cells appear atypical, including inflammation, infection, and normal aging. Atypical cells can change back to normal cells if the underlying cause is removed or resolved. Atypia is often used in cytopathology to fill the gap between what is recognized as entirely normal and what is recognized as clearly abnormal. The term "atypical" was introduced by Dr. George N. Papanicolaou, the founder of modern cytodiagnosis, to convey a very low suspicion of (pre)malignancy. The term "atypia" has an ambiguous and imprecise definition, and its optimal use is uncertain. A clinically meaningful, standardized cytodiagnostic category of "atypia" requires a narrow definition, quantitative criteria, agreed-upon reference images, a clear clinical meaning, and well-defined management options.