Oropharynx - Pathology

()Map ALIMENTARY SYSTEM (Map)

Introduction

See anatomy and physiology of the oral cavity

Proliferative Pathology

Neoplastic

Adenomas

Oral Papilloma Neoplasia in Dog (Courtesy of Alun Williams (RVC))

• Adenomas are unusual but may develop in oropharyngeal salivary tissue.

Melanomas

• Melanomas can arise anywhere in the oral cavity and are almost invariably malignant with early and widespread metastasis.
• Many are poorly pigmented or even amelanotic and may only be distinguished from squamous carcinomas by histological examination.

Papillomas

• The common benign epithelial tumour of the oropharynx is the papilloma, which is very often caused by infection with certain types of species-specific papilloma viruses.

Squamous cell Carcinoma

Papilloma and Squamous Cell Carninoma of Epiglottis (Courtesy of Alun Williams (RVC))

• Squamous cell carcinomas are the malignant equivalent of the papilloma and may arise anywhere within the oropharynx.
  • Those arising over the tonsil (squamous carcinoma of the tonsil or tonsillar carcinoma) are very malignant, invading adjacent tissues and metastasising early.
  • Squamous carcinomas of the tongue (especially in cats) can also behave in a very malignant fashion. Those at more rostral sites, e.g. on the incisor gingivae, are less likely to metastasise early although they may be locally aggressive.
  • Squamous cell carcinomas of the oropharynx in cattle are commonly seen as part of an upper alimentary tract carcinoma complex.

Other Neoplasms

Fibrosarcoma (Courtesy of Alun Williams (RVC))

• Both benign and malignant connective tissue tumours do occur,
  • e.g. fibroma, fibrosarcoma, osteoma, osteosarcoma.

Traumatic Pathology

Stick injuries in dog

• Sticks may damage to pharynx with oedema and swelling in pharynx and secondary infection.
• Pieces of wood may remain embedded in back of throat resulting in chronic inflammation.
• Can kill dog.

Learning Tools

Oropharynx Flashcards