GIT Pathology 2 Flashcards
- Pathological processes that can cause oral masses.
- Non-neoplastic mass types.
- Neoplastic mass types.
- Inflammation, hypertrophy/hyperplasia, neoplasia.
- Inflammatory and reactive hyperplastic or proliferative responses, cysts.
- Benign, benign but invasive, malignant.
- What does epulis mean?
- Types of non-neoplastic reactive gingival tumour-like lesions.
- Non-specific clinical term sometimes used to describe a gingival growth. Purely descriptive, not diagnostic.
- Gingival hyperplasia or fibrous hyperplasia.
Others:
Pyogenic granuloma (uncommon), peripheral giant cell granuloma (rare).
Drug-induced gingival enlargement (Phenytoin, Calcium Channel Blockers, Cyclosporine).
Gingival hyperplasia or fibrous hyperplasia.
Common in dogs.
Boxer dog predisposed.
Result from chronic low-grade irritation.
Can be focal, multifocal or generalised.
Usually close to teeth.
Pedunculated or sessile (broad base) masses.
Smooth or rough.
May be ulcerated.
- Non-neoplastic canine oral papillomatosis.
- In what other spp.?
- Canine papillomavirus-1 infection.
Hyperplastic epithelial response to viral infection - lips, tongue, pharynx, oesophagus.
Usually resolve spontaneously (4-8w). - Cattle - often extends further down into the oesophagus and sometimes the forestomachs.
How can oral neoplasia be divided?
Dental tissue origin or non-dental tissue origin.
Oral dental neoplasia from dental tissue origin.
Peripheral odontogenic fibroma.
Canine acanthomatous ameloblastoma.
Peripheral odontogenic fibroma.
Arises from periodontal ligament.
Common in dogs, less common in cats, rare in horses.
Benign.
Fibrous (collagenous) tissue - firm.
May contain hard tissues e.g. bone, cementum, dentin.
Canine acanthomatous (spiky) ameloblastoma.
Arises from odontogenic epithelium.
Particular type of ameloblastoma seen in dogs.
Most common in adult medium to large breed dogs.
Most frequently affects rostral mandible.
Benign so does not metastasise.
BUT often has aggressive behaviour w/ invasion of bone.
Non-dental tissue oral neoplasia types.
SCC.
Malignant melanoma.
Fibrosarcoma.
Other = plasmacytoma, lymphoma, MCT, osteosarcoma.
SCC.
Most common oral neoplasm in cats.
Second most common malignant oral neoplasm in dogs.
General features:
- arises from stratified squamous mucosa lining the oral cavity, pharynx (and tonsils) and larynx.
- malignant.
- locally invasive.
- mets lately in clinical course.
Common sites of SCC in oral cavity of a cat.
Appearance of early disease.
Activity?
Ventral surface of tongue/sublingual close to frenulum.
Gingiva.
Early tumour may appear as a small, raised, fleshy mass, or as an ulcerated area.
Highly invasive to soft tissues and bone, may metastasise to local LNs (submandibular, retropharyngeal), rarely to lung.
Common sites of SCC in dogs.
Gingiva (+ tonsils – more likely mets).
Locally invasive to bone.
Mets later on to local LNs, less commonly to the lungs.
Malignant melanoma.
Common sites?
Activity?
Appearance?
Most common malignant neoplasm in dogs.
Horses don’t tend to get these as primary tumours in the oral cavity.
Gums and lips commonly.
Often highly malignant - local bone invasion, mets to local LNs and often distant sites e.g. lung.
Often sessile, some pedunculated.
May be ulcerated.
Variable degree of pigmentation.
- can get amelanotic melanomas.
Fibrosarcoma.
Common sites?
Activity?
3rd most common oral malignancy in dogs.
2nd mist common oral neoplasm in cats.
Gingiva, palate.
Infiltrative - may invade bone.
May metastasise in dogs - more commonly regional LNs, less commonly lungs.
Has a low metastatic potential in cats.
Oral neoplasms in proportion to all neoplasms in spp. and their malignancies.
5% of all neoplasms are oral neoplasms in dogs w/ 65% malignancy.
6-10% of all neoplasms are oral neoplasms in cats w/ 90% malignancy.
0-1.1% of all neoplasms are oral neoplasms in horses w/ most being malignant.
Oral neoplasms are rare in cattle.
- except after ingestion of bracken fern due to carcinogens in it - neoplasia incl. in alimentary tract.
