Fig. 3.

Histologic features of PSCCA. a Low power histomicrograph demonstrating the prominent papillary nature of neoplastic proliferation surrounding fibrovascular cores and minimal surface keratinization (H&E, ×2 magnification). b Low power features demonstrating the verrucoid papillary nature with bulbous rete ridges with keratin pearl formation from a different case. (H&E, ×4 magnification). c Papillary proliferation with elongated and bulbous rete ridge formation. (H&E, ×4 magnification). d Higher magnification of case in image c demonstrating individual cell keratinization and keratin pearl formation. (H&E, ×10 magnification)