The histopathological features of canine keratinizing ameloblastoma

This paper describes the microscopical features of one variant of canine ameloblastoma. It is composed of islands and strands of odontogenic epithelium that have infiltrated through the surrounding stroma. Most of the basal cells are hyperchromatic, cuboidal and perpendicular to the basement membrane (palisading); in some areas their nuclei are located at the distal ends of the cells (reverse polarization) and their cytoplasm is vacuolated. These are the classical characteristics of the basal cell layer of ameloblastomas. The central cells of these tumours are closely-packed, spindle-shaped and exhibit cellular keratinization and calcification as prominent features. Amyloid is present between the neoplastic epithelial cells in some examples.