Page 1409 - Cote clinical veterinary advisor dogs and cats 4th

712 Oral Tumors, Benign

Epidemiology • Peripheral odontogenic fibroma (also called Etiology and Pathophysiology
SPECIES, AGE, SEX fibromatous and ossifying epulides): ossifying • Cause is unknown, but genetic predisposition
VetBooks.ir odontogenic fibroma, acanthomatous amelo- cementum-like tissue within the soft-tissue • Some benign masses are suspected to undergo
may play a role.
epulides may contain bone-, dentin-, or
• Dogs: usually gingival hyperplasia, peripheral
swelling; minimally invasive
malignant transformation, although this
blastoma; occasionally pyogenic granuloma,
dentigerous cyst, odontoma, papilloma,
osteoma, plasmacytoma; rarely giant cell • Giant cell granuloma (giant cell tumor, seems to be rare.
giant cell epulis): rare; rapid growth with
epulis, amyloid-producing odontogenic inflammatory and ulcerative changes, osteoid DIAGNOSIS
tumor (APOT) and woven bone formation; multinucleated
• Cats: usually proliferative inflammatory giant cell is main component in mass; rapid Diagnostic Overview
tissue; occasionally giant cell epulis, osteoma, recurrence after incomplete excision; thought Diagnosis of benign oral masses usually
plasmacytoma; rarely peripheral odontogenic to be a variant of the peripheral odontogenic requires histopathologic exam of an incisional
fibroma, acanthomatous ameloblastoma, fibroma or excisional biopsy specimen because many
inductive ameloblastoma (feline inductive • Ameloblastoma: central (intraosseous) oral masses do not exfoliate well on cytologic
odontogenic tumor), APOT, odontoma, or peripheral (extraosseous); both locally sampling.
gingival hyperplasia invasive, but central ameloblastoma often
• Benign oral tumors can occur at any age. exhibiting cystic bony changes; acantho- Differential Diagnosis
• Oral papillomas (p. 752) usually occur matous ameloblastoma in dogs historically • Normal anatomy (e.g., incisive papilla caudal
in dogs < 2 years old or older dogs with classified as acanthomatous epulis but to maxillary incisors in dogs and cats; lingual
concurrent immunopathy. probably similar to peripheral ameloblastoma molar gland caudolingual to mandibular first
• Feline inductive odontogenic tumor usually • Feline inductive odontogenic tumor: rare; molar teeth in cats): if the mass is located
occurs in cats < 2 years old. occurs most commonly in the rostral maxilla directly on the midline or is bilateral, consult
• Odontogenic tumors (arising from tooth- of cats < 2 years of age; may be locally an anatomy textbook to rule out normal
forming tissue) can occur at any age, but invasive but does not metastasize structures before performing a biopsy.
tumors in young pets are more likely to be • APOT: rare; previously called calcifying • Scar tissue (chewing lesions from traumatiz-
of odontogenic origin. epithelial odontogenic tumor; may be ing buccal or sublingual mucosa)
locally invasive in dogs and cats but does • Eosinophilic granuloma (p. 300): on tongue,
GENETICS, BREED PREDISPOSITION not metastasize lips, and palate
• Peripheral odontogenic fibroma (previously • Plasmacytoma (plasma cell tumor): extra- • Inflammatory swelling due to foreign body
called fibromatous epulis and ossifying medullary variant at nasal, pharyngeal, and • Apical abscess (p. 7)
epulis): more common in brachycephalic oral mucosa that has no apparent primary • Osteomyelitis/bone sequestrum: usually
dog breeds bone involvement; sessile or polypoid sessile seen in the incisive bone or bilaterally in
• Oral tumors in cats are rarely benign. and usually solitary oral masses appear to the caudal mandible or maxilla; often appears
remain localized as bony swelling with gingival recession,
CONTAGION AND ZOONOSIS • Osteoma: slow growing; composed of well- erosion, and ulceration; exposed bone; and
Oral papillomas in young dogs are caused by differentiated, densely sclerotic, compact fetid odor. Cocker spaniels and dachshunds
species-specific canine papillomavirus. bone may be overrepresented.
• Cementoma: odontogenic neoplasm of mes- • Gingival hyperplasia
ASSOCIATED DISORDERS enchymal origin, consisting of cementum- • Dentigerous cyst: arising around tooth that
• Gingival hyperplasia like tissue deposited by cells resembling has not erupted
• Malignant oral tumors cementoblasts • Craniomandibular osteopathy (CMO): most
• Granular cell tumor (myoblastoma): uncer- commonly seen in West Highland white,
Clinical Presentation tain histogenesis, most commonly occurring Scottish, and Cairn terriers; mandibular
DISEASE FORMS/SUBTYPES on the tongue swellings associated with CMO are often
• Gingival hyperplasia: abnormal increase in bilateral.
the number of normal cells in a normal HISTORY, CHIEF COMPLAINT • Malignant oral tumors (p. 714)
arrangement, resulting in clinical enlargement • Focal swelling of gingiva and/or alveolar
or thickening of gingiva mucosa commonly noted as an incidental Initial Database
• Pyogenic granuloma: usually developing on finding • CBC, serum biochemistry profile, and
gingiva/alveolar mucosa caudobuccal to the • Benign oral tumors rarely present with oral urinalysis: generally unremarkable
mandibular first molar in cats; consisting of bleeding or halitosis unless they are large • Thoracic radiographs: benign tumors do not
markedly vascular granulation tissue with enough to be traumatized by opposing cause metastasis
endothelial proliferation, generally ulcerated teeth on closure of the mouth. Bleeding at
and inflamed, commonly with hemosiderin the lesion site is a common complaint in Advanced or Confirmatory Testing
deposits dogs with a large acanthomatous amelo- • Anesthetized oral exam (p. 1140)
• Dentigerous (tooth-containing) cyst (fol- blastoma. • Dental radiography: various bony changes
licular cyst): develops around the crown of • CT: particularly helpful for maxillary
an unerupted tooth PHYSICAL EXAM FINDINGS masses
• Odontoma: not a true tumor but considered • Focal swelling of gingiva/alveolar mucosa is • Cytologic exam of aspirated oral masses and
to be a hamartoma (accumulation of normal often circumscribed and rarely ulcerated. lymph nodes
epithelial and mesenchymal odontogenic • Benign tumors that are locally invasive (e.g., • Histopathologic evaluation of incisional or
cells arranged in an abnormal manner but canine acanthomatous ameloblastoma) may excisional biopsy
allowing for induction of dental hard tissues) cause disfigurement secondary to invasion
○ Compound odontoma: hard tissues of the maxilla or mandible. TREATMENT
produced in a relatively organized manner, • Displaced teeth (but uncommonly mobile)
resulting in tooth-like structures • Mandibular lymph nodes are often normal. Treatment Overview
○ Complex odontoma: dental hard tissue • Appetite and activity level are usually • Marginal resection (removal of the mass and
bearing no resemblance to a tooth unaffected. a small amount of unaffected surrounding

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