Changes

=Introduction=

=Introduction=

[[Image:oral squamous cell carcinoma.jpg|right|thumb|200px|<center>'''Oral squamous cell carcinoma'''. Courtesy of T. Scase</center>]]

[[Image:oral squamous cell carcinoma.jpg|right|thumb|200px|<center>'''Oral squamous cell carcinoma'''. Courtesy of T. Scase</center>]]

Squamous cell carcinomas are the '''malignant''' equivalent of the [[papilloma]] and may arise anywhere within the [[Oropharynx - Anatomy & Physiology|oropharynx]]. These tumours are formed from '''epidermal cells''' with varying degrees of '''squamous cell differentiation'''. They are common in the cat, dog, horse and cow but can occur in other species. They are most likely to develop in '''non-pigmented areas''' of the skin as there is a known association between their development and exposure to '''UV light'''.

'''Squamous cell carcinomas (SCC)''' are '''malignant''' tumours commonly seen in the cat, dog, horse and cow. They are most likely to develop in '''non-pigmented areas''' of the skin as there is a known association between their development and exposure to '''UV light'''. The tumours are normally '''slow to metastasize''' but may be locally invasive.

There are two forms of the neoplasm:

There are two forms of the neoplasm:

* '''Ulcerative''' — ulcerative lesions

* '''Ulcerative''' — ulcerative lesions

The tumours are normally '''slow to metastasize''' but may be locally invasive.

Histologially, the tumours are formed from '''epidermal cells''' with varying degrees of '''squamous cell differentiation'''.

==Cat==

==Cat==

==Horse==

==Horse==

'''Cutaneous''' SCC's are the second most common neoplasms in the horse. Contact with '''penile smegma''' is thought to be an additional predisposing cause. They are most commonly located in the '''penile''' or '''clitoral''' regions and on '''non-pigmented''' skin. Lesions are '''progressive''' and potentially '''locally invasive'''. They may be '''ulcerative''' or '''proliferative''' and '''secondary infection''' is often present, producing a foul odour.  Complete '''surgical excision''' is the gold standard treatment, but '''adjuncts''' may be required. Masses located around the eye may need prompt specialist treatment to save the eye.

'''Cutaneous''' SCC's are the second most common neoplasms in the horse. Contact with '''penile smegma''' is thought to be an a predisposing cause. They are most commonly located in the '''penile''' or '''clitoral''' regions and on '''non-pigmented''' skin. Lesions are '''progressive''' and potentially '''locally invasive'''. They may be '''ulcerative''' or '''proliferative''' and '''secondary infection''' is often present, producing a foul odour.  Complete '''surgical excision''' is the gold standard treatment, but '''adjuncts''' may be required. Masses located around the eye may need prompt specialist treatment to save the eye.

SCC of the '''stomach''' is the most common gastric tumour in the horse. It has the appearance of a large '''cauliflower-like mass''' and affects the '''pars oesophagea'''. It metastasises and spreads and '''transcoelomically'''.

SCC of the '''stomach''' is the most common gastric tumour in the horse. It has the appearance of a large '''cauliflower-like mass''' and affects the '''pars oesophagea'''. It metastasises and spreads and '''transcoelomically'''.

=Diagnosis=

=Diagnosis=

[[File:Well differentiated squamous cell carcinoma.jpg|thumb|right|150px|'''Well differentiated squamous cell carcinoma''' (Wikimedia Commons)]]

[[File:Well differentiated squamous cell carcinoma.jpg|thumb|right|150px|'''Well differentiated squamous cell carcinoma''' (Wikimedia Commons)]]

FNA's can be performed as a first line diagnostic. '''Cytology''' may show:

FNA's should be performed as a first line diagnostic test on any suspicious mass. '''Cytology''' may show:

* Pleomorphic epithelial cells - these have a variable appearance from benign keratinized mature squames to epithelial cells with anisocytosis, basophilic cytoplasm and extensive vacuolation.

* Pleomorphic epithelial cells - these have a variable appearance from benign keratinized mature squames to epithelial cells with anisocytosis, basophilic cytoplasm and extensive vacuolation.

* Binucleate cells, chromatin clumping and prominent nucleoli may be present

* Binucleate cells, chromatin clumping and prominent nucleoli may be present

   

   

Any mass suspicious of squamous cell carcinoma should be '''biopsied''' to confirm diagnosis.

A '''biopsy''' should always be performed to confirm diagnosis.

[[Category:Neoplasia]]

[[Category:Neoplasia]]

[[Category: To Do - Siobhan Brade]]

[[Category: To Do - Siobhan Brade]]