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.
Major salivary glands in the cat.
Parotid, mandibular, sublingual, zygomatic.
Also have molar salivary gland, on the mandible, lingual to the molar tooth, in a membranous molar pad.
- True salivary cysts.
- Pseudocysts (sialoceles).
- Ranula.
- Salivary gland duct blockage.
- due to congenital atresia/FB/salivary calculi/inflammation/strictures.
- duct remains intact»_space; cystic dilation of the salivary gland or duct(s). - Salivary gland duct rupture (often small intraglandular duct).
- saliva pooling in soft tissues stimulate encapsulation and mild inflammation
» fluid-filled cavity in soft tissues of mouth or neck.
– mucocele = mucus content.
– serocele = serous content. - Smooth, rounded, fluctuant, cystic swelling on the floor of the mouth.
- may be true salivary cyst or pseudocyst.
Sialoadenitis.
Causes?
Possible result.
Inflammation of the salivary glands.
Uncommon.
Causes = infection via duct or haematogenous spread, or trauma.
May cause duct obstruction.
- glandular atrophy may result from partial or complete duct obstruction or chronic inflammation.
Salivary gland infarction name?
What is it?
Cause?
Necrotising sialometaplasia.
Rare in cats and dogs (small terriers).
Areas of salivary gland infarction w/ coagulative necrosis, inflammation and swelling - variable pain.
Cause poorly understood - trauma?
‘Sialometaplasia’ refers to metaplastic, reactive epithelial response (change in mature type of cell).
Neoplasia of the salivary glands.
Uncommon.
Mostly epithelial, mostly malignant (carcinomas and adenocarcinomas).
Sx resection difficult due to location.
Types of pathologies in the oesophagus.
Obstruction.
Inflammation.
Neoplasia.
Megaoesophagus.
Mechanical obstruction of the oesophagus.
Intraluminal obstruction (occlusion) e.g. FB, food.
Intramural obstruction (stenosis) e.g. tumour, inflammation.
Extrinsic obstruction (compression) e.g. tumour, abscess, enlarged LNs, congenital vascular ring e.g. persistent right aortic arch causing obstruction and dilation of oesophagus.
- Examples of causes of intraluminal obstruction of the oesophagus (occlusion).
- Predisposed sites of the oesophagus for intraluminal obstruction.
- Further consequences of intraluminal oesophageal obstruction.
- Potatoes, root veg (ruminants), fibrous ingesta e.g. sugar beet +/- dehydration (horses).
Bones (dogs and cats).
Toys (dogs). - Larynx, thoracic inlet, heart base, diaphragmatic hiatus.
- Secondary oesophagitis, lacerations, pressure necrosis of oesophageal mucosa, scarring and stricture, perforation and peri-oesophageal cellulitis.
Inflammation of the oesophagus (oesophagitis) causes.
Trauma or obstruction e.g. FB, choke.
Viral disease e.g. mucosal disease/BVDV.
Reflux of gastric acid (reflux oesophagitis)
- e.g. chronic gastric regurgitation or v+, GA.
Ingestion of caustic/irritant chemicals, plants or drugs e.g. Doxycycline in cats.
Oesophageal neoplasia.
Rare/uncommon.
Mostly SCC.
- cattle – bracken fern grazing.
- may infiltrate local tissues.
- may metastasise to regional LNs.
Papillomas (viral) - cattle – related to papillomavirus.
Megaoesophagus.
Dilated hypomotile oesophagus.
Unable to effectively transport food from pharynx to the stomach.
Muscular dysfunction»_space; failure of peristalsis
» accumulation of ingesta in oesophagus»_space; oesophageal dilation, regurgitation, may have secondary oesophagitis, ulceration etc.
Megaoesophagus causes.
Congenital - dogs, cats, horses, cattle.
Acquired - conditions affecting nerve function or muscle function involved in oesophageal peristalsis, e.g.:
– idiopathic.
– neuro disease e.g. peripheral neuropathies, dysautonomia, toxins (e.g. lead), trauma (e.g. vagal nerve injury).
– neuromuscular diseases e.g. myasthenia gravis, polymyositis.
– hypoadrenocorticism (rare).
– prolonged oesophageal obstruction (distension can become permanent).
