Type of Preparation: Conventional Magnification: High Clinical History: 27 year old, post-partum, routine Pap smear. Interpretation: NILM: Atrophy, post-partum Cytomorphologic Criteria: A sheet of parabasal cells is present without any evidence of more advanced maturation. Explanatory Notes: Parabasal cells and metaplasia may be difficult to distinguish from squamous metaplasia and can appear occasionally as "hyperchromatic clusters". The background cells and history provide clues. Follow-up: None