Category:Oral Cavity - Proliferative Pathology

Hyperplastic

Polychlorinated Napthalene Poisoning

Papular

Orf

• Pox infection
• Quite a common zoonotic disease

Papular proliferative pathology

Clinical

• In sheep produces a proliferative nodule/papular mass on lips
• In flocks in which it is endemic it is seen in lamb
• If flock is non-immune seen in ewes too but much worse in lambs (may spread to inside of mouth)
• Can spread to udder of ewe

Pathology

• Poxvirus infections produce local infection of prickle cells in epithelium with proliferation of cells and formation of papule followed by ulceration / necrosis and covered by necrotic epithelium
• Eventually scabs form and crust drops off
• Scabs - very infectious ( N.B.if touch -> catch it)

Bovine Papular stomatitis

Ring Zone Lesions of BPS - Calf (Courtesy of Alun Williams (RVC))

• Parapox virus
• Very similar disease to orf but seen in cattle and generally milder condition.
• Must be differentiated from Foot and Mouth Disease and Mucosal Disease.
• Sporadic, in cattle, less than 1 year old.
• Develop papules on the muzzle, external nares and in the oral cavity; the oesophagus and forestomachs may also be affected.
• Usually heals spontaneously.

Pathogenesis

• The early lesions are round areas of intense congestion up to 1.5 cm in diameter.
• The centre becomes necrotic and slightly depressed.
• Slow peripheral extension of this lesion gives a classical ring zone formation with concentric rings of
  • yellow (necrosis),
  • grey (epithelial hyperplasia)
  • red (congestion).

Histology

• There are focal areas of hydropic degeneration in the stratum spinosum
• Large eosinophilic intracytoplasmic inclusion
• Epidermis is markedly thickened.
• The superficial layers of the epithelium become necrotic and slough.
• Vesicle formation is not a feature of this disease.

Papilloma

Neoplastic

Squamous cell carcinoma

Oral squamous cell carcinoma. Courtesy of T. Scase

neoplastic