Fig. 1

a Cytologic features of normal squamous epithelial cells with small pyknotic nuclei (Pap, x200). b Low-grade squamous intraepithelial lesion with Human Papilloma Viral changes (Pap, x400). c High-grade squamous intraepithelial lesion. Nuclei are greatly enlarged, vary in size and shape, and contain hyperchromatic, coarsely granular clumped chromatin (Pap, x400). d Invasive SCC showing nests of neoplastic squamous cells invading through a chronically inflamed stroma (H&E, x200)