Oral Mucosal Hyperplasia & Neoplasia Flashcards
where are Oral Mucosal Hyperplasia & Neoplasia most common in vet med?
in dogs & cats
What is hyperplastic gingivitis?
- usually associated w/ periodontal disease & chronic irritation by plaque or tartar that initially starts as inflammation (gingivitis) but can progress to severe hyperplastic gingivitis
- this needs to be differentiated by histopathology from gingival hyperplasia & epulis
What is gingival hyperplasia (hypertrophy) in dogs?
- simple overgrowth of gum tissue consisting of the fibrous submucosa lined by hyperplastic gingival epithelium which is not driven by an inflammatory process as in hyperplastic gingivitis
- grossly it can be indistinguishable from gingival epulis
Why is it important to distinguish btwn hyperplastic gingivitis & gingival hyperplasia?
b/c different treatment & prognosis (in some cases)
Who is gingival hyperplasia most common in?
brachycephalic dog breeds & is present in ~30% of boxers older than 5 years
What causes gingival hyperplasia?
- breed predisposition, medications (immunosuppressants, Ca-channel blockers, anticonvulsants), idiopathic
What is canine oral papillomatosis?
- it is papillomavirus induced, transmissible, & occurs in animals younger than 1 year
- lesions usually regress spontaneously & immunity is long-lasting
What is an epulis?
nonspecific exophytic gingival mass
what is a fibromatous epulis (peripheral odontogenic fibroma)?
- of periodontal ligament origin
- a benign tumour of dental mesenchyme
What is a Acanthomatous ameloblastoma (Acanthomatous epulis)?
- benign but invasive tumour that arises from epithelial tooth germ
- invasion & distraction of bone is common
How do you differentiate a Acanthomatous ameloblastoma (Acanthomatous epulis) from a fibromatous epulis?
Histology
How do you cure a Acanthomatous ameloblastoma (Acanthomatous epulis)?
radical & complete excision (ex: partial mandibulectomy)
What are the malignant oral tumours of dogs? (listed in order of frequency)
- oral melanoma
- squamous cell carcinoma
- fibrosarcoma
- osteosarcoma
What is the prognosis for oral melanoma in dogs?
- “kiss of death” (70% have distant mets)
- melanotic & amelanotic types, but no prognostic difference
(remember not all of them are black on gross exam)
Is there therapy for an oral melanoma in dogs?
- therapy (ex: radiation) improves life, but is not curative, due to early distant metastasis
What is the prognosis for oral squamous cell carcinomas in dogs?
- less aggressive than feline SCC
- locally invasive & regional lymph node metastasis
- initially only locally invasive, hence early diagnosis & radical excision is imperative for prolonged survival
- various locations -> different prognoses (tonsilar SCC has shorter survival (>60% distant mets & very invasive) than gingival SCC (<5% distant mets but locally invasive)
What is the prognosis for oral fibrosarcoma in dogs?
- usually locally invasive (< 20% distant mets)
What is the prognosis for oral Osteosarcoma in dogs?
- better compared to limb osteosarcoma due to its lower metastatic potential
- even w/ radical therapy, median survival ranges btwn 6 & 18 months (longer for mandibular than maxillary origin)
What are benign masses of cat mouths?
- “nothing good grows in a cat’s mouth” is a useful generalization but not completely correct
- oral eosinophilic granulomas are benign masses
- exuberant granulation tissue at sites of previous ulceration can present like a nodular mass (this is a benign process secondary to a problem w/ healing or repair)
What are malignant oral tumours in cats?
- Squamous cell carcinoma
- oral lymphosarcoma & fibrosarcoma
What are oral squamous cell carcinomas in cats like?
- most common oral neoplasia in cats & it is much more aggressive than its canine counterpart
- initially feline SCCs may not look proliferative & often present as a mildly osteolytic lesion of the tooth sockets or subgingival bone or as non-healing sublingual ulcers
- feline SCCs are often quite aggressive & invade local subadjacent tissues, regional lymph nodes, & may have distant metastasis
- postoperative survival is less than 1 year in the majority of cases
Frequency of oral lymphosarcoma & fibrosarcomas in cats?
occur but not as frequently as SCCs
What therapeutic results do we see with oral melanomas in dogs & oral squamous cell carcinomas in cats?
- it seems that various therapeutic approaches improve greatly the quality of life & postpone the need for premature euthanasia, however overall eventual case fatality rates remain the same
How do oral papillomas behave in dogs?
usually self-limiting by developed long lasting immunity
