Type of Preparation: Conventional Magnification: High Clinical History: 47 year old female, HIV+ Interpretation: HSIL, features suspicious for invasion Cytomorphologic Criteria: Numerous abnormal cells are present in varying sizes and shapes. Nuclei vary from round to oval to spindle shaped. This type of pleomorphism suggests invasive carcinoma. However, the absence of nucleoli and necrosis are consistent with CIS. Explanatory Notes: The distinction between CIS and invasive carcinoma may be difficult when cells are numerous and display variation in nuclear size and shape. Follow-up: CIS with gland involvement; no invasion