Fig. 3
From: Orthokeratinized odontogenic cysts: a Spanish tertiary care centre study based on HPV DNA detection
Recurrence of an OOC. Panoramic view showing the wall of a cystic lesion with large areas of hyperplastic verrucous growth with central filling by keratin (a), which is highlighted by PAS staining (b). Hyperplastic verrucous growth shows an endophytic and “pushing” well-differentiated pattern (c). Deeper portions showed epithelial nests with mild atypia and basement membrane integrity (d), which in the immunohistochemical analysis demonstrated proliferative cellular activity (Ki67 positivity) not restricted to the basal cell layer (e), as well as diffuse nuclear p53 reactivity (f)