Type of Preparation: Conventional Magnification: High Interpretation: Squamous cell carcinoma - non keratinizing Cytomorphologic Criteria: Numerous isolated cells display nuclei with irregular membranes, uneven chromatin distribution, hyperchromasia, and irregular membranes. While the cells display all the features of HSIL, they also contain nucleoli, and markedly irregular distribution of chromatin. An associated tumor diathesis is often present, but is not pictured. Explanatory Notes: It has been suggested that large numbers of isolated cells may be a clue as to the severity a squamous epithelial lesion.