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
How does gingival oral hyperplasia behave in dogs?
benign
How do oral fibromatous epulis behave in dogs?
benign
How do oral acanthomatous ameloblastomas behave in dogs?
locally invasive
How do oral melanomas behave in dogs?
locally invasive & highly metastatic - distant mets
How do oral squamous cell carcinomas behave in dogs?
locally invasive w/ local LN metastasis
How do oral fibrosarcomas behave in dogs?
locally invasive w/ local LN metastasis
How does oral eosinophilic granulomas behave in cats?
benign
How do oral squamous cell carcinomas behave in cats?
locally invasive w/ LN & potential distant metastasis
How do oral fibrosarcomas behave in cats?
- locally invasive with LN metastasis
How do oral lymphosarcomas behave in cats?
(rare)
- poor prognosis if multicentric
hyperplastic gingivitis
gingival hyperplasia
gingival hyperplasia
gingival epulis (gingival mass or tumour)
fibromatous epulis w/ lymphoplasmacytic hyperplastic gingivitis
oral melanoma
oral fibrosarcoma
squamous cell carcinoma in Fe
Benign vs malignant, invasive vs non-invasive, and the most common canine invasive oral tumours?
