Type of Preparation: Conventional Magnification: High Interpretation: HSIL Cytomorphologic Criteria: HSIL (CIS) cells are seen in a syncytial arrangement of cells with hyperchromatic nuclei and a high nuclear to cytoplasmic ratio. The loss of polarity and dense cytoplasm are consistent with CIS . Explanatory Notes: CIS can be seen in a syncytial pattern as demonstrated here or in smaller groups or as isolated cells. Additionally the cytoplasm in HSIL cells maybe dense (metaplastic), immature/ lacy/ non-metaplastic or keratinized. Compare this pattern of CIS with images showing endocervical gland involvement by HSIL.