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Category:Intestines - Proliferative Pathology (view source)
Revision as of 19:33, 6 June 2010
, 19:33, 6 June 2010Created page with '==Introduction== * Tumours may develop from any of the components of the intestinal wall. ** May be of either a benign or malignant variation. * Tumours have a wide range of eff…'
==Introduction==
* Tumours may develop from any of the components of the intestinal wall.
** May be of either a benign or malignant variation.
* Tumours have a wide range of effects on intestinal funtion.
*# Many malignant tumours cause intestinal obstruction at their point of origin.
*#* E.g. intestinal adenocarcinomas, solitary lymphomas.
*#* Onset is often gradual (unlike most foreign bodies)
*#* Benign tumours can also cause obstruction, but this is most likely if they
*#** Protrude into the lumen
*#** Are located at a compressible site, e.g. within the pelvis, at the duodenal flexure.
*# Tumours that diffusely infiltrate the mucosa cause diahorrea due to malabsorption and development of a protein losing enteropathy.
*#* E.g. diffuse alimentary lymphoma.
*# Benign or malignant tumours can result in mucosal erosion or ulceration.
*#* Blood is lost, causing haemorrhagic anaemia.
*#** Prolonged bleeding can cause iron deficiency anaemia.
*#* Extensive tumour necrosis may occur due to rapid growth or secondary infection.
*#** This can cause gradual or sudden perforation and peritonitis.
== Adenocarcinoma ==
* An '''intestinal adenocarcinoma''' is a malignancy of epithelial cells from the intestinal mucosa.
* Found in both the [[Small Intestine - Anatomy & Physiology|small]] and [[Large Intestine - Anatomy & Physiology|large intestines]]
** Common in the canine [[Rectum - Anatomy & Physiology|rectum]].
* Species affected:
** Fairly common in dog and cat.
** Seen related to bracken ingestion in the older sheep.
** Occasionally occur in horses.
* These tumours usually grow away from the mucosa, down through the muscularis mucosae and into the submucosa, muscular layers and the serosa.
** They may, however, project into the lumen.
* Intestinal adeocarcinomas may take an annular form.
** This may result in stenosis of lumen
*** Muscle proximal to the lesion becomes hypertrophied and dilated.
* Spread may be
*# Via the lympahtics.
*#* To the lymph nodes, lung and [[Liver - Anatomy & Physiology|liver]].
*# Transcoelomic spread
*#* Small, white plaques on serosa and adjacent tissues e.g. diaphragm.
== Lymphoma ==
* Lymphoma occurs in both the small and [[Large Intestine - Anatomy & Physiology|large intestine]]s.
* Is a relatively common neoplasm of the cat and dog.
* Causes a diffuse spread of neoplastic lymphocytes through the mucosa and the rest of the wall.
** Leads to malabsorption and therefore [[Diarrhoea|diarrhoea]] and the development of a protein losing enteropathy.
== Mast cell tumours ==
== Intestinal stromal tumours ==
==Tumours of the Perianal Area==
===Hepatoid Gland Tumours (Perianal Adenomas)===
[[Image:normal perianal gland.jpg|thumb|right|100px|Perianal gland- normal (Courtesy of Bristol BioMed Image Archive)]] * Affect the dog.
* Arise from the solid, modified sebaceous circumanal glands.
* Common in ageing entire males. [[Image:perianal gland adenoma histopath.jpg|thumb|100px|Perianal gland- adenoma (Courtesy of Bristol BioMed Image Archive)]]
* Lesions range from hyperplasia to true adenomas (benign).
** These low grade lesions are under hormonal control.
*** Castration/ administation of oestrogens or anti-androgens causes reduction in size.[[Image:perianal gland adenoma.jpg|thumb|right|100px|Perianal adenoma- gross appearance (Courtesy of Bristol BioMed Image Archive)]]
* Occasionally hepatoid carcinomas (malignant) arise in affected males
** Outwith hormonal control.
* Hepatoid gland tumours occur rarely in bitches.
** Are commonly malignant.
* Hepatoid glands are also found at the tail head, prepuce and occasionally other skin sites.
** Hepatoid tumours can also arise in these areas.
===Adenocarcinomas of the Glands of the Anal Sac (Apocrine Glands)===
* Apocrine glands are the true anal glands- not to be confused with the anal sacs or the perianal glands.
* Much less common than intestinal adenocarcinoma.
* Commoner in bitches than dogs.
* Can be bilateral.
* Consequences:
** May cause local problems.
** May metastasise.
** Often secrete a parahormone-like substance to cause paraneoplastic syndrome.
*** This can arise even when the primary tumour is very small.
*** Results in bone resorption and hypercalcaemia,
**** In turn can cause renal failure. which in turn can cause renal failure.[[Category:Intestines,_Small_and_Large_-_Pathology]]
* Tumours may develop from any of the components of the intestinal wall.
** May be of either a benign or malignant variation.
* Tumours have a wide range of effects on intestinal funtion.
*# Many malignant tumours cause intestinal obstruction at their point of origin.
*#* E.g. intestinal adenocarcinomas, solitary lymphomas.
*#* Onset is often gradual (unlike most foreign bodies)
*#* Benign tumours can also cause obstruction, but this is most likely if they
*#** Protrude into the lumen
*#** Are located at a compressible site, e.g. within the pelvis, at the duodenal flexure.
*# Tumours that diffusely infiltrate the mucosa cause diahorrea due to malabsorption and development of a protein losing enteropathy.
*#* E.g. diffuse alimentary lymphoma.
*# Benign or malignant tumours can result in mucosal erosion or ulceration.
*#* Blood is lost, causing haemorrhagic anaemia.
*#** Prolonged bleeding can cause iron deficiency anaemia.
*#* Extensive tumour necrosis may occur due to rapid growth or secondary infection.
*#** This can cause gradual or sudden perforation and peritonitis.
== Adenocarcinoma ==
* An '''intestinal adenocarcinoma''' is a malignancy of epithelial cells from the intestinal mucosa.
* Found in both the [[Small Intestine - Anatomy & Physiology|small]] and [[Large Intestine - Anatomy & Physiology|large intestines]]
** Common in the canine [[Rectum - Anatomy & Physiology|rectum]].
* Species affected:
** Fairly common in dog and cat.
** Seen related to bracken ingestion in the older sheep.
** Occasionally occur in horses.
* These tumours usually grow away from the mucosa, down through the muscularis mucosae and into the submucosa, muscular layers and the serosa.
** They may, however, project into the lumen.
* Intestinal adeocarcinomas may take an annular form.
** This may result in stenosis of lumen
*** Muscle proximal to the lesion becomes hypertrophied and dilated.
* Spread may be
*# Via the lympahtics.
*#* To the lymph nodes, lung and [[Liver - Anatomy & Physiology|liver]].
*# Transcoelomic spread
*#* Small, white plaques on serosa and adjacent tissues e.g. diaphragm.
== Lymphoma ==
* Lymphoma occurs in both the small and [[Large Intestine - Anatomy & Physiology|large intestine]]s.
* Is a relatively common neoplasm of the cat and dog.
* Causes a diffuse spread of neoplastic lymphocytes through the mucosa and the rest of the wall.
** Leads to malabsorption and therefore [[Diarrhoea|diarrhoea]] and the development of a protein losing enteropathy.
== Mast cell tumours ==
== Intestinal stromal tumours ==
==Tumours of the Perianal Area==
===Hepatoid Gland Tumours (Perianal Adenomas)===
[[Image:normal perianal gland.jpg|thumb|right|100px|Perianal gland- normal (Courtesy of Bristol BioMed Image Archive)]] * Affect the dog.
* Arise from the solid, modified sebaceous circumanal glands.
* Common in ageing entire males. [[Image:perianal gland adenoma histopath.jpg|thumb|100px|Perianal gland- adenoma (Courtesy of Bristol BioMed Image Archive)]]
* Lesions range from hyperplasia to true adenomas (benign).
** These low grade lesions are under hormonal control.
*** Castration/ administation of oestrogens or anti-androgens causes reduction in size.[[Image:perianal gland adenoma.jpg|thumb|right|100px|Perianal adenoma- gross appearance (Courtesy of Bristol BioMed Image Archive)]]
* Occasionally hepatoid carcinomas (malignant) arise in affected males
** Outwith hormonal control.
* Hepatoid gland tumours occur rarely in bitches.
** Are commonly malignant.
* Hepatoid glands are also found at the tail head, prepuce and occasionally other skin sites.
** Hepatoid tumours can also arise in these areas.
===Adenocarcinomas of the Glands of the Anal Sac (Apocrine Glands)===
* Apocrine glands are the true anal glands- not to be confused with the anal sacs or the perianal glands.
* Much less common than intestinal adenocarcinoma.
* Commoner in bitches than dogs.
* Can be bilateral.
* Consequences:
** May cause local problems.
** May metastasise.
** Often secrete a parahormone-like substance to cause paraneoplastic syndrome.
*** This can arise even when the primary tumour is very small.
*** Results in bone resorption and hypercalcaemia,
**** In turn can cause renal failure. which in turn can cause renal failure.[[Category:Intestines,_Small_and_Large_-_Pathology]]