LIGHT-MICROSCOPIC, ULTRASTRUCTURAL, AND IMMUNOHISTOCHEMICAL EXAMINATIONS OF 2 CALCIFYING EPITHELIAL ODONTOGENIC-TUMORS (CEOT) IN A DOG AND A CAT

Two calcifying epithelial odontogenic tumors from a 10-year-old cross-breed dog and a 9-year-old cat were characterized histologically and electron microscopically. Important characteristics were plexiform to squamous epithelial structure, amyloid in the tumor tissue with partial calcification (Liesegang's rings), and a low rate of mitosis. The amyloid found in the tumors was subjected to immunohistochemical examination, using a series of antibodies (anti-AA, -AL, -AF, -ASc(1), -AB, -cytokeratin, -vimentin, -desmin, -laminin). The exclusive reaction to anti-cytokeratin and anti-laminin suggests that the amyloid is of epithelial origin.