Changes

==Introduction==

==Introduction==

An adenoma is a '''benign epithelial tumour''' arising in the epithelium of the '''mucosa''' (stomach and intestines), '''glands''' (endocrine and exocrine) and '''ducts'''.  

An adenoma is a '''benign epithelial tumour''' arising in the epithelium of the '''mucosa''' (stomach and intestines), '''glands''' (endocrine and exocrine) and '''ducts'''.  

Adenomas observed in veterinary species include:

Adenomas observed in veterinary species include:

==Perianal adenoma==

==Perianal Adenoma==

[[Image:normal perianal gland.jpg|thumb|right|100px|Perianal gland- normal (Courtesy of Bristol BioMed Image Archive)]]

[[Image:normal perianal gland.jpg|thumb|right|200px|Perianal gland - normal (Courtesy of Bristol BioMed Image Archive)]]

 

====Clinical features====

====Clinical features====

Adenomas occur alone or in number, as round, well-differentiated, freely-movable masses. Tumours can become ulcerated and secondarily infected. There can be signs of perianal pain and tenesmus.

Adenomas occur alone or in number, as round, well-differentiated, freely-movable masses. Tumours can become ulcerated and secondarily infected. There can be signs of perianal pain and tenesmus.

====Diagnosis====

====Diagnosis====

'''Cytology''' of the mass will reveal large hepatoid cells with a round, central nuclei, multiple nucleoli, and an abundant cytoplasm. There may be concurrent inflammation or haemorrhage. Cytology cannot distinguish adenomas from [[Adenocarcinoma#Perianal gland adenocarcinoma|adenocarcinomas]], and further investigations should be carried out if malignancy is suspected.

'''Cytology''' of the mass will reveal large hepatoid cells with a round, central nuclei, multiple nucleoli, and an abundant cytoplasm. There may be concurrent inflammation or haemorrhage. Cytology cannot distinguish adenomas from [[Adenocarcinoma#Perianal gland adenocarcinoma|adenocarcinomas]], and further investigations should be carried out if malignancy is suspected.

====Treatment====

====Treatment====

'''Castration''' is the treatment of choice and 95% of tumours will regress. Administration of oestrogens or anti-androgens can also be considered, but side-effects of those hormones should not be forgotten. Surgical removal of the tumour may be necessary if it is large, or in females.

'''Castration''' is the treatment of choice and 95% of tumours will regress. Administration of oestrogens or anti-androgens can also be considered, but side-effects of those hormones should not be forgotten. Surgical removal of the tumour may be necessary if it is large, or in females.

It can be difficult to differentiate from an adenocarcinoma, and '''immunohistochemistry''' has been used for this purpose.  

This is a tumour of the '''apocrine sweat gland''' and is rare in dogs and cats. It can be difficult to differentiate from an adenocarcinoma, and '''immunohistochemistry''' has been used for this purpose.  

Adenomas rarely ulcerate, are associated with '''little local inflammation''' and have a cystic feel on palpation.

Adenomas rarely ulcerate, are associated with '''little local inflammation''' and have a cystic feel on palpation.

Wide surgical excision usually carries a good prognosis.

Wide surgical excision usually carries a good prognosis.

==Ceruminous gland adenoma==

==Ceruminous Gland Adenoma==

This occurs with some frequency in dogs and cats, and is thought to be linked to the '''presence of long-standing [[Otitis Externa - Cat and Dog|otitis externa]]''', leading to increased glandular dysplasia.  

This occurs with some frequency in dogs and cats, and is thought to be linked to the '''presence of long-standing [[Otitis Externa - Cat and Dog|otitis externa]]''', leading to increased glandular dysplasia.  

These tumours usually occur in older animals, and conservative local resection is usually sufficient to manage them.

These tumours usually occur in older animals, and conservative local resection is usually sufficient to manage them.

==Sebaceous gland adenoma==

==Sebaceous Gland Adenoma==

These are common in older dogs and cats and are usually distinctly '''wart-like or cauliflower-like''' in appearance.

These are common in older dogs and cats and are usually distinctly '''wart-like or cauliflower-like''' in appearance.

The prognosis is good with surgical resection.

The prognosis is good with surgical resection.

==Salivary gland adenoma==

==Salivary Gland Adenoma==

This tumour is rare in animals, and the malignant adenocarcinoma is much more common.

This tumour is rare in animals, and the malignant adenocarcinoma is much more common.

==Mammary gland adenoma==

==Mammary Gland Adenoma==

This is a benign tumour which is quite common in cats and dogs.  

This is a benign tumour which is quite common in cats and dogs.  

Find out more information on [[Mammary Neoplasia|mammary tumours]].

Find out more information on [[Mammary Neoplasia|mammary tumours]].

==Intestinal adenoma==

==Intestinal Adenoma==

 

[[Image:brunner gland adenoma.jpg|thumb|right|20px|Adenoma of brunners glands (duodenum) (Courtesy of Bristol BioMed Image Archive)]]

[[Image:brunner gland adenoma.jpg|thumb|right|150px|Adenoma of brunners glands (duodenum) (Courtesy of Bristol BioMed Image Archive)]]

 

Intestinal adenomas are found in both the [[Small Intestine Overview - Anatomy & Physiology|small]] and [[Large Intestine - Anatomy & Physiology|large intestines]]. Intestinal adenomas usually grow into the lumen and can be called '''adenomatous polyps'''.

Intestinal adenomas are found in both the [[Small Intestine Overview - Anatomy & Physiology|small]] and [[Large Intestine - Anatomy & Physiology|large intestines]]. Intestinal adenomas usually grow into the lumen and can be called '''adenomatous polyps'''.

Depending on the type of the insertion base, the adenoma may be '''pedunculated''' with a long stalk, or '''sessile''' with a broad base. This influences the method of resection and the rate of recurrence, as pedunculated tumours are much more easily removed.

Depending on the type of the insertion base, the adenoma may be '''pedunculated''' with a long stalk, or '''sessile''' with a broad base. This influences the method of resection and the rate of recurrence, as pedunculated tumours are much more easily removed.

==Hepatic adenoma==

==Hepatic Adenoma==

It is seen mostly in '''sheep and cattle'''.

It is seen mostly in '''sheep and cattle''' and usually presents as a single, pale, soft, often large nodule, which is well demarcated from adjacent tissue, often with a noticeable capsule. The tissue has a '''normal hepatocytic appearance'''. No portal tracts can be seen within the mass and a capsule surrounds the growth.

==Cholangiocellular Adenoma==

 

Also called '''biliary adenoma''', it is very rare but has been reported in dogs and cats. It shows an expansive growth and consists of slightly dilated, occasionally cystic structures, lined with cuboidal or flattened, well differentiated biliary epithelium.

 

==Cholangiocellular adenoma==

Also called '''biliary adenoma''', it is very rare but has been reported in dogs and cats.

 

It shows an expansive growth and consists of slightly dilated, occasionally cystic structures, lined with cuboidal or flattened, well differentiated biliary epithelium.

 

[http://w3.vet.cornell.edu/nst/nst.asp?Fun=Image&imgID=7754 Image of multifocal pancreatic adenoma in a dog from Cornell Veterinary Medicine]

[http://w3.vet.cornell.edu/nst/nst.asp?Fun=Image&imgID=7754 Image of multifocal pancreatic adenoma in a dog from Cornell Veterinary Medicine]

Adenoma of the '''exocrine (zymogen) cells of the pancreas''' is known in several species and is recognised by its ductal or acinar pattern of cells, with an expanding growth pattern and '''complete encapsulation'''. Cystic spaces may be created by the tumour cells, which may also project in a papillary pattern into the lumen of the cysts.

Adenoma of the '''exocrine (zymogen) cells of the pancreas''' is known in several species and is recognised by its ductal or acinar pattern of cells, with an expanding growth pattern and '''complete encapsulation'''. Cystic spaces may be created by the tumour cells, which may also project in a papillary pattern into the lumen of the cysts.

 

[[Category:To Do - Review]]

[[Category:Expert Review]]

 

[[Category:Oropharynx - Pathology]]

[[Category:Oropharynx - Pathology]]

[[Category:Intestines - Proliferative Pathology]]

[[Category:Intestines - Proliferative Pathology]]

[[Category:Liver, Primary Tumours]]

[[Category:Liver, Primary Tumours]]

[[Category:Pancreas_-_Hyperplastic_and_Neoplastic_Pathology]]

[[Category:Pancreas_-_Hyperplastic_and_Neoplastic_Pathology]]

[[Category:Neoplasia]]

[[Category:Neoplasia]]