VETERINARY DENTISTRY AT WORK Maxillary Calcifying Epithelial Odontogenic Tumor in a Siberian Tiger (Panthera tigris altaica) A great diversity of neoplasms have been reported in captive wild felids, but most reports describe single cases of benign tumors.1-3 Only two previous studies reported specific data about the prevalence of neoplasia in captive wild felids. Both studies were based on the prevalence at necropsy.4,5 Cancer is an uncommon cause of disease and death in captive wild felids and few neoplasms have been described in lions. Among the tumors reported in captive lions, the most commonly affected sites are the skin and subcutaneous tissue and included cutaneous mast cell tumor, basal cell epithelioma, mammary duct carcinoma, and subcutaneous fibrosarcoma. Neoplasms of the alimentary system have also been reported including gastric carcinoma, biliary tract malignant lymphoma, and two cases of gallbladder adenocarcinoma.6 Reports of neoplasia in Panthera species are increasing, primarily because of their increased longevity in captivity, as well as the prevalence of diagnostic biopsies and necropsies.7 Ameloblastoma and calcifying epithelial odontogenic tumor (calcifying epulis) are considered non-inductive towards connective tissue, while ameloblastic fibroma (fibromatous epulis), dentinoma, ameloblastic odontoma, complex odontoma, and compound odontoma have an inductive influence on the oral mesenchyme.8,9 Calcifying epithelial odontogenic tumors (CEOT) are characterized by epithelial proliferation, mineralization of the epithelium and stroma, and deposition of amyloid or amyloid-like substances.8,10 With the exception in dogs and cats, the CEOT is rarely reported in animals.8,11 Furthermore, the tumors reported as CEOT in animals are not equivalent to those in humans. In humans, CEOT is dominated by sheets of eosinophilic epithelial cells that often exhibit considerable nuclear pleomorphism.8 Whereas CEOT in animals is noted by palisades of basal cells and stellate reticulum. It has been proposed that amyloid-producing odontogenic tumor (APOT) be considered an alternative term for CEOT in animals.8
Case Report
A male, adult Siberian tiger (Panthera tigris altaica) was anesthetized and diagnosed with periodontal disease during a routine examination in October 2005. However, dental treatment was not possible because the necessary equipment was unavailable. After 30-months, a new chemical restraint for general evaluation was necessary, since the tiger was presenting with anorexia, polydipsia, and progressive weight loss. The oral examination revealed periodontal disease and a 2.0-cm, pink tumor with a smooth, regular surface at the right maxillary canine tooth (104) [Fig. 1]. A complete periodontal treatment was accomplished and the tumor was surgically removed with radiosurgery and submitted for histopathological evaluation (Fig. 2). Histological sections of the oral mucosa showed an ulcerative lesion partially covered by stratified squamous epithelium with ulcerated areas
Figure 1 Photograph in a male, adult Siberian tiger (Panthera tigris altaica) showing a 2.0-cm calcifying epithelial odontogenic tumor (CEOT) at the right maxillary canine tooth (104).
Figure 2
Intraoperative (A) and immediate postoperative (B) photographs showing resection of a 2.0-cm calcifying epithelial odontogenic tumor (CEOT) in an adult Siberian tiger (Panthera tigris altaica) at the right maxillary canine tooth (104) using radiosurgery.
J VET DENT Vol. 32 No. 2 Summer 2015
120
and a mixed inflammatory infiltrate. There was also acanthotic oral epithelium with preserved cellular differentiation of keratinocytes and increased stromal fibroblastic density particularly in submucosa. Fibroblast cells were characterized by loose chromatin and evident nucleoli, indicating increased metabolic activity. There was sporadic deposition of hyaline acidophilic matrix and frequent mineralization of collagen (Fig. 3). Odontogenic epithelium and evidence of malignancy were absent. The histological diagnosis was calcifying epithelial odontogenic tumor (CEOT). The tiger died 3-months later from complications of advanced renal disease. Increased longevity due to better nutrition, management, and veterinary care could be logical reasons for the increased incidence of neoplasia in zoo collections, although neoplasms do not appear to greatly affect the average age of death.4,5
This increase in prevalence may also be due to environmental factors, particularly carcinogens, which play a role in the development of neoplasias in zoo felids. Most of the zoos are located directly adjacent to urban areas. Therefore, it seems possible that particulates and emissions from automobiles and other sources could play a role in cancer development in these animals. High levels of automobile emissions are suspected of causing higher levels of neoplasia in humans and have been shown to have carcinogenic properties in laboratory animals.12 Neoplasms of the digestive system and oral cavity in tigers are rare. Of the more prevalent neoplasms in felids, only 4.25 % occurred in tigers and none were reported to affect the digestive system.5 To our knowledge, this is the first report of a CEOT in the Siberian tiger (Panthera tigris altaica).
Figure 3
Contributed by:
Histomicrographic images of a calcifying epithelial odontogenic tumor (CEOT) in an adult Siberian tiger (Panthera tigris altaica). Note the increase in stromal fibroblastic density and cells with less chromatin and evident nucleoli, indicating intense metabolic activity. There are foci of hyaline acid deposition and frequent mineralization (A) [H&E, original magnification = 10X]. At higher magnification, note the typical fibroblastic cellularity and intense collagen formation along with dominant mineralization (B) [H&E, original magnification = 40X].
Roberto Silveira Fecchio, DVM, MSc1; Marcelo da Silva Gomes, DVM, MSc2; José Guilherme Xavier, DVM, MSc, PhD³; Patricia Edith Kunze4; Marco Antonio Gioso, DVM, DDS, MSc, PhD1 1 2 3 4
Laboratory of Comparative Dentistry (Fecchio, Gioso) LOC-FMVZ-USP – Brazil Av. Prof. Dr. Orlando de Marques Paiva, 87, Bloco 8-superior, Cidade Universitária, São Paulo, SP 05508-270, Brazil São Bernardo`s Zoo (Gomes) – Brazil, Rua Portugal, 1100, Riacho Grande, São Bernardo do Campo, SP 09831-000, Brazil Programa de Pós-graduação em Patologia Ambiental e Experimental (Xavier), Universidade Paulista (UNIP) – Brazil, Rua Dr. Bacelar, 1212, Vila Clementino, São Paulo, SP 04026-002, Brazil College of Veterinary Medicine and Animal Sciences of the University of São Paulo (Kunze) FMVZ-USP – Brazil, Av. Prof. Dr. Orlando Marques de Paiva, 87, Cidade Universitária, São Paulo, SP 05508-270, Brazil. Email: [email protected]
References 1. Douglass EM. Lymphosarcoma and blockage of the biliary duct in an African lion (Panthera leo). Vet Med Small Anim Clin 1979; 74: 1637. 2. Gilette DM, Acland HM, Klein L. Ductular mammary carcimoma in a lioness. J Am Vet Med Assoc 1978; 173: 1099-1102. 3. Marker L, Munson L, Basson PA, et al. Multicentric T-cell lymphoma associated with feline leukemia virus infection in a captive Namibian cheetah (Acinonyx jubatus). J Wildl Dis 2003; 39: 690-695. 4. Lombard LS, Witte EJ. Frequency and types of tumors in mammals and birds of the Philadelphia Zoological Garden. Cancer Res 1959; 19: 127-141. 5. Owston MA, Ramsay EC, Rotstein DS. Neoplasia in felids at the Knoxville Zoological Gardens. J Zoo Wildl Med 1979-2003; 39: 608-613. 6. Dorso L, Risi S et al. High-Grade mucoepidermoid carcinoma of the mandibular salivary gland in a lion (Panthera leo). Vet Pathol 2008; 45:104-108. 7. Tucker AR, Ramsay EC, Donnell RL. Oligodendroglioma in an african lion (Panthera leo.) J Zoo Wildl Med 2008; 39: 650-654. 8. Gardner DG. An orderly approach to the study of odontogenic tumours in animals. J Comp Pathol 1992; 107: 427-438. 9. Poulet FM, Valentine BA, Summers BA. A survey of epithelial odontogenic tumors and cysts in dogs and cats. Vet Pathol 1992; 29: 369-380. 10. Philipsen HP, Reichart PA. Calcifying epithelial odontogenic tumor: biological profile based on 181 cases from the literature. Oral Oncol 2000; 36:17-26. 11. Kang MS, Park MS, et al. Amyloid-producing odontogenic tumor (Calcifying Epithelial Odontogenic Tumor) in the mandible of a Bengal tiger (Panthera tigris tigris). J Comp Pathol 2006; 134: 236–240. 12. Møller P, Folkmann JK, et al. Air pollution, oxidative damage to DNA, and carcinogenesis. Cancer Lett 2008; 266: 84-97.
121
J VET DENT Vol. 32 No 2 Summer 2015
Case Report
A male, adult Siberian tiger (Panthera tigris altaica) was anesthetized and diagnosed with periodontal disease during a routine examination in October 2005. However, dental treatment was not possible because the necessary equipment was unavailable. After 30-months, a new chemical restraint for general evaluation was necessary, since the tiger was presenting with anorexia, polydipsia, and progressive weight loss. The oral examination revealed periodontal disease and a 2.0-cm, pink tumor with a smooth, regular surface at the right maxillary canine tooth (104) [Fig. 1]. A complete periodontal treatment was accomplished and the tumor was surgically removed with radiosurgery and submitted for histopathological evaluation (Fig. 2). Histological sections of the oral mucosa showed an ulcerative lesion partially covered by stratified squamous epithelium with ulcerated areas
Figure 1 Photograph in a male, adult Siberian tiger (Panthera tigris altaica) showing a 2.0-cm calcifying epithelial odontogenic tumor (CEOT) at the right maxillary canine tooth (104).
Figure 2
Intraoperative (A) and immediate postoperative (B) photographs showing resection of a 2.0-cm calcifying epithelial odontogenic tumor (CEOT) in an adult Siberian tiger (Panthera tigris altaica) at the right maxillary canine tooth (104) using radiosurgery.
J VET DENT Vol. 32 No. 2 Summer 2015
120
and a mixed inflammatory infiltrate. There was also acanthotic oral epithelium with preserved cellular differentiation of keratinocytes and increased stromal fibroblastic density particularly in submucosa. Fibroblast cells were characterized by loose chromatin and evident nucleoli, indicating increased metabolic activity. There was sporadic deposition of hyaline acidophilic matrix and frequent mineralization of collagen (Fig. 3). Odontogenic epithelium and evidence of malignancy were absent. The histological diagnosis was calcifying epithelial odontogenic tumor (CEOT). The tiger died 3-months later from complications of advanced renal disease. Increased longevity due to better nutrition, management, and veterinary care could be logical reasons for the increased incidence of neoplasia in zoo collections, although neoplasms do not appear to greatly affect the average age of death.4,5
This increase in prevalence may also be due to environmental factors, particularly carcinogens, which play a role in the development of neoplasias in zoo felids. Most of the zoos are located directly adjacent to urban areas. Therefore, it seems possible that particulates and emissions from automobiles and other sources could play a role in cancer development in these animals. High levels of automobile emissions are suspected of causing higher levels of neoplasia in humans and have been shown to have carcinogenic properties in laboratory animals.12 Neoplasms of the digestive system and oral cavity in tigers are rare. Of the more prevalent neoplasms in felids, only 4.25 % occurred in tigers and none were reported to affect the digestive system.5 To our knowledge, this is the first report of a CEOT in the Siberian tiger (Panthera tigris altaica).
Figure 3
Contributed by:
Histomicrographic images of a calcifying epithelial odontogenic tumor (CEOT) in an adult Siberian tiger (Panthera tigris altaica). Note the increase in stromal fibroblastic density and cells with less chromatin and evident nucleoli, indicating intense metabolic activity. There are foci of hyaline acid deposition and frequent mineralization (A) [H&E, original magnification = 10X]. At higher magnification, note the typical fibroblastic cellularity and intense collagen formation along with dominant mineralization (B) [H&E, original magnification = 40X].
Roberto Silveira Fecchio, DVM, MSc1; Marcelo da Silva Gomes, DVM, MSc2; José Guilherme Xavier, DVM, MSc, PhD³; Patricia Edith Kunze4; Marco Antonio Gioso, DVM, DDS, MSc, PhD1 1 2 3 4
Laboratory of Comparative Dentistry (Fecchio, Gioso) LOC-FMVZ-USP – Brazil Av. Prof. Dr. Orlando de Marques Paiva, 87, Bloco 8-superior, Cidade Universitária, São Paulo, SP 05508-270, Brazil São Bernardo`s Zoo (Gomes) – Brazil, Rua Portugal, 1100, Riacho Grande, São Bernardo do Campo, SP 09831-000, Brazil Programa de Pós-graduação em Patologia Ambiental e Experimental (Xavier), Universidade Paulista (UNIP) – Brazil, Rua Dr. Bacelar, 1212, Vila Clementino, São Paulo, SP 04026-002, Brazil College of Veterinary Medicine and Animal Sciences of the University of São Paulo (Kunze) FMVZ-USP – Brazil, Av. Prof. Dr. Orlando Marques de Paiva, 87, Cidade Universitária, São Paulo, SP 05508-270, Brazil. Email: [email protected]
References 1. Douglass EM. Lymphosarcoma and blockage of the biliary duct in an African lion (Panthera leo). Vet Med Small Anim Clin 1979; 74: 1637. 2. Gilette DM, Acland HM, Klein L. Ductular mammary carcimoma in a lioness. J Am Vet Med Assoc 1978; 173: 1099-1102. 3. Marker L, Munson L, Basson PA, et al. Multicentric T-cell lymphoma associated with feline leukemia virus infection in a captive Namibian cheetah (Acinonyx jubatus). J Wildl Dis 2003; 39: 690-695. 4. Lombard LS, Witte EJ. Frequency and types of tumors in mammals and birds of the Philadelphia Zoological Garden. Cancer Res 1959; 19: 127-141. 5. Owston MA, Ramsay EC, Rotstein DS. Neoplasia in felids at the Knoxville Zoological Gardens. J Zoo Wildl Med 1979-2003; 39: 608-613. 6. Dorso L, Risi S et al. High-Grade mucoepidermoid carcinoma of the mandibular salivary gland in a lion (Panthera leo). Vet Pathol 2008; 45:104-108. 7. Tucker AR, Ramsay EC, Donnell RL. Oligodendroglioma in an african lion (Panthera leo.) J Zoo Wildl Med 2008; 39: 650-654. 8. Gardner DG. An orderly approach to the study of odontogenic tumours in animals. J Comp Pathol 1992; 107: 427-438. 9. Poulet FM, Valentine BA, Summers BA. A survey of epithelial odontogenic tumors and cysts in dogs and cats. Vet Pathol 1992; 29: 369-380. 10. Philipsen HP, Reichart PA. Calcifying epithelial odontogenic tumor: biological profile based on 181 cases from the literature. Oral Oncol 2000; 36:17-26. 11. Kang MS, Park MS, et al. Amyloid-producing odontogenic tumor (Calcifying Epithelial Odontogenic Tumor) in the mandible of a Bengal tiger (Panthera tigris tigris). J Comp Pathol 2006; 134: 236–240. 12. Møller P, Folkmann JK, et al. Air pollution, oxidative damage to DNA, and carcinogenesis. Cancer Lett 2008; 266: 84-97.
121
J VET DENT Vol. 32 No 2 Summer 2015
