Type of Preparation: Conventional Magnification: Medium Interpretation: HSIL Cytomorphologic Criteria: "Keratinizing dysplasia". The dysplastic cells in this field display enlarged nuclei with coarsely granular chromatin and keratinized cytoplasm. Occasional cells have pyknotic or opaque nuclei with sharp, angled edges and abnormal cell shapes are seen. Nuclear size and degree of abnormality exceed the cytomorphology of "atypical parakeratosis" yet are not supportive of an invasive lesion. Explanatory Notes: The criteria of N/C ratio and degree of nuclear abnormalities used for grading SIL may be more difficult to apply to keratinizing lesions. The extent of abnormality here qualifies for an interpretation of HSIL.