Type of Preparation: Conventional Magnification: High Clinical History: Postmenopausal female Interpretation: NILM : Histiocytes Cytomorphologic Criteria: Histiocytes. These cells have moderate, often vacuolated cytoplasm and kidney shaped to oval vesicular nuclei. Nucleoli may be seen. Explanatory Notes: Histiocytes can be seen in postmenopausal and postpartum Pap tests and can be single or multinucleated. They may be also be seen secondary to other reactive/reparative processes. Superficial endometrial cells can resemble histiocytes. At low power, the differential diagnosis of single cells in a "streaming" pattern, often in mucus includes histiocytes, microglandular hyperplasia and even HSIL.