Changes

==Description==  

==Description==  

Gastric [[Neoplasia - Pathology|neoplasia]] is uncommon and represents less than 1% of neoplasia in small animals. Aetiology is largely idiopathic though long term ingestion of dietary carcinogens may have some responsibility. In humans, ''Helicobacter pylori'' can induce gastric carcinomas and lymphomas. Its role in gastric tumours in dogs and cats has not yet been fully established though it is known to cause gastritis and ulceration. Belgian Shepherd dogs may have a genetic predisposition to gastric carcinomas. Cats with gastric lymphomas are usually FeLV positive.

Gastric [[Neoplasia - Pathology|neoplasia]] is uncommon and represents less than 1% of neoplasia in small animals. Aetiology is largely idiopathic though long term ingestion of dietary carcinogens may have some responsibility. In humans, ''Helicobacter pylori'' can induce gastric carcinomas and lymphomas. Its role in gastric tumours in dogs and cats has not yet been fully established though it is known to cause [[Gastritis, Acute|gastritis]] and [[Gastric Ulceration - all species|ulceration]]. Belgian Shepherd dogs may have a genetic predisposition to gastric carcinomas. Cats with gastric lymphomas are usually FeLV positive.

Malignant tumours include:

Malignant tumours include:

Anterior abdominal pain may or may not be present

Anterior abdominal pain may or may not be present

Adenocarcinomas: frequently metastasise to the regional lymph nodes (gastroduodenal and splenic lymph nodes), also the liver and sometimes the lungs. They are also locally aggressive and can cause stomach wall perforation resulting in peritonitis. Other complications include pyloric outflow obstruction and ischaemic necrosis where tumour plugs develop in the surrounding vasculature.

Adenocarcinomas: frequently [[Neoplasia - Pathology#The Process of Metastasis| metastasise]] to the regional [[Lymph Nodes - Anatomy & Physiology|lymph nodes]] (gastroduodenal and splenic lymph nodes), also the [[Liver - Anatomy & Physiology |liver]] and sometimes the [[Lungs - Anatomy & Physiology|lungs]]. They are also locally aggressive and can cause stomach wall perforation resulting in [[Peritonitis|peritonitis]]. Other complications include pyloric outflow obstruction and ischaemic necrosis where tumour plugs develop in the surrounding vasculature.

Leiomyosarcomas: rarely metastasise.  

Leiomyosarcomas: rarely metastasise.  

Lymphoma: may be limited to the stomach, may affect lymph nodes and other abdominal organs or may be multicentric.  

Lymphoma: may be limited to the stomach, may affect lymph nodes and other abdominal organs or may be multicentric.  

===Haematology and biochemistry===

===Haematology and biochemistry===

A Regerative anaemia may be present due to gastric haemorrhage. [[Electrolytes|Electrolyte]] disturabnces will be evident following vomiting and also elevated [[Urea|BUN]] and creatinine levels due to dehydration.

A Regerative anaemia may be present due to gastric haemorrhage. [[Electrolytes|Electrolyte]] disturabnces will be evident following vomiting and also elevated [[Urea|BUN]] and creatinine levels due to [[Dehydration - Pathology|dehydration]].

If hepatic metastasis has occured or if there is obstruction to the common bile duct hepatic enzymes will also be increased.

If hepatic metastasis has occured or if there is obstruction to the common bile duct hepatic enzymes will also be increased.

==Treatment==

==Treatment==

===Surgery===

===Surgery===

Prior to any surgical intervention thoracic radiography should be performed for evidence of metastasis. Regional lymph nodes should also be examined at the start of surgery along with the rest of the abdominal cavity. For tumours that have not metastasised, resection is the treatment of choice (wide partial gastrectomy or antrectomy with gastroduodenostomy (Billroth 1). However, frequently there are  difficulties as tumours are often in an advanced stage at time of presentation. Excision with large margins whilst maintaining the ability to sucessfully reconstruct the stomach without post-operative complications can be problematic. Futhermore, pylorectomy and gastroduodenostomy or gastrojejunostomy for antral tumours risk iatrogenic trauma to the local blood supply as well as to the pancreas and extrahepatic biliary system. Neoplasia associated with the lesser curvature is generally non-resectable.

Prior to any surgical intervention thoracic radiography should be performed for evidence of metastasis. Regional lymph nodes should also be examined at the start of surgery along with the rest of the abdominal cavity. For tumours that have not metastasised, resection is the treatment of choice (wide partial gastrectomy or antrectomy with gastroduodenostomy. However, frequently there are  difficulties as tumours are often in an advanced stage at time of presentation.  

Excision with large margins whilst maintaining the ability to sucessfully reconstruct the stomach without post-operative complications can be problematic. Futhermore, pylorectomy and gastroduodenostomy or gastrojejunostomy for antral tumours risk iatrogenic trauma to the local blood supply as well as to the pancreas and extrahepatic biliary system.  

Neoplasia associated with the lesser curvature is generally non-resectable.

===Chemotherapy===

===Chemotherapy===

===Other Medical Management===

===Other Medical Management===

Symptomatic therapy of for example vomiting may improve quality of life in the short term. Treatment options include anti-emetics such as metocolpramide and H2 blockers including ranitidine and cimetidine.  

Symptomatic therapy of for example vomiting may improve quality of life in the short term. Treatment options include [[Emetics and Anti-Emetic Drugs|anti-emetics]] such as metocolpramide and H2 blockers including ranitidine and cimetidine.  

==Prognosis==

==Prognosis==

Lymphoma often has a poor response to chemotherapy and survival rates are low.

Lymphoma often has a poor response to chemotherapy and survival rates are low.

Most malignant tumours are associated with recurrent or metastatic cancer. Prognosis therefore usually poor despite surgical resection. Survival time up to six months.

Most malignant tumours are associated with recurrent or metastatic cancer. Prognosis therefore usually poor despite surgical resection. Survival time up to six months.

Extramedullary plasmacytomas - can have a very good prognosis following surgery and chemotherapy.

Extramedullary plasmacytomas can have a very good prognosis following surgery and chemotherapy.

==References==

==References==