Light Microscopic, Ultrastructural, and Immunohistochemical Examinations of Two Calcifying Epithelial Odontogenic Tumors (CEOT) in a Dog and a Cat

Abstract

Abstract. Two calcifying epithelial odontogenic tumors from a 10-year-old cross-breed dog and a 9-yearold 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,, -AB, -cytokeratin, -vimentin, -desmin, -laminin). The exclusive reaction to anti-cytokeratin and anti-laminin suggests that the amyloid is of epithelial origin.

Oral Masses in Two Cats

“…1,3,5,7,9,17 It is often referred to as calcifying epithelial odontogenic tumor (CEOT), according to its similarities to the human counterpart. 3,18,19 However, the human CEOT, or Pindborg tumor, is not totally equivalent to the CEOT in animals. 5,14 Animal CEOTs often show palisaded basal cells and stellate reticulum, 5 neither of which is common in human CEOTs.…”

Biochemical and Immunohistochemical Characterization of the Amyloid in Canine Amyloid-Producing Odontogenic Tumor

“…19,20,29,32,37,42,43 The amyloid of canine and feline APOT did not react immunohistochemically with antibodies to human cytokeratins, human vimentin, chicken desmin, laminin, human collagen (types I, III, IV), or amyloid A; the neoplastic epithelial cells reacted only with anti-human cytokeratins. 29 Breuer et al 2 evaluated animal APOTs immunohistochemically with a panel of antibodies to amyloid A (AA protein), immunoglobulin light chain protein in amyloidosis (AL protein), amyloid protein in familial amyloidotic polyneuropathy (AF protein), amyloid fibril proteins in senile cardiac amyloid (ASc1 protein), amyloid b protein in senile plaque amyloid (AB protein), cytokeratins, vimentin, desmin, and laminin and suggested that the amyloid in CEOT was epithelial in origin based on the exclusive immunoreaction to anticytokeratin and antilaminin 2 Another investigator reported that the neoplastic epithelial cells expressed cytokeratins AE1/AE3, neuron-specific enolase, and S-100 protein but that the amyloid deposits did not express cytokeratins AE1/AE3. 46 Basement membrane components 37 and cytokeratins 1,19,42 have been proposed as the origin for the amyloid; however, in another study, the amyloid lacked immunoreactivity for basement membrane components (laminin 1 and 5, collagen type IV, fibronectin) or pan-cytokeratins.…”

“…30 The origin of the amyloid in human and animal CEOT is often debated but is still unknown. 2,19,27,29,37,42,46 Recent studies indicate that the amyloid in human CEOT is secreted by the neoplastic epithelial cells, but its precise nature remains unclear. 27,39,42 CEOT in veterinary medicine is classified as amyloidproducing odontogenic tumor (APOT).…”

“…21,51 Localized amyloid deposits with or without association with neoplasia also have been described in the human mammary gland, 41,52 respiratory tract, 26,34 gastrointestinal tract, 5,38 genitourinary tract, 13,17 skin, 24,25 and bone. 23 In animals, localized amyloidosis has been associated with neoplastic conditions such as calcifying epithelial odontogenic tumor (CEOT), 2,29 pancreatic endocrine tumor, 28 medullary thyroid carcinoma, 15 ameloblastoma, 10 mammary carcinoma, 43 intestinal carcinoid, 40 extramedullary plasmacytoma, 31,36 and myeloma. 12 CEOT is a rare neoplasm of the tooth-forming apparatus that produces a mineralized substance and amyloid.…”

Protein folding pathology in domestic animals

“…Other types of amyloid less frequently encountered in animal species, are AapoAI (Roertgen et al, 1995) or AApoAII (Gruys et al, 1996), localised AL amyloid (Van Andel et al, 1988a;Ramos-Vara et al, 1998;Platz et al, 1997), amyloid in odontogenic tumours (Gardner et al, 1994;Breuer et al, 1994) or mammary tumours (Taniyama et al, 2000) and amyloid in brain tissues: Aβ in old dogs and AprP sc in sheep with scrapie (Van Keulen et al, 1995) (>50% in a small series of Dutch cases (Gruys, 1988).…”