Difference between revisions of "Gastric Neoplasia - Dog and Cat"
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{{Unfinished}} | {{Unfinished}} | ||
| − | More | + | More frequent compared with oesophageal neoplasia but still uncommon accounting for less than 1% of all malignancies. Malignant tumours include: |
| − | * [[Stomach and Abomasum Proliferative - Pathology #Adenocarcinoma|Adenocarcinoma]] - 70-80% of | + | * [[Stomach and Abomasum Proliferative - Pathology #Adenocarcinoma|Adenocarcinoma]] - 70-80% of all canine gastric neoplasms |
* [[Stomach and Abomasum Proliferative - Pathology #Squamous cell carcinoma|Squamous Cell Carcinoma]] | * [[Stomach and Abomasum Proliferative - Pathology #Squamous cell carcinoma|Squamous Cell Carcinoma]] | ||
| − | * [[Stomach and Abomasum Proliferative - Pathology #Lymphoma|Lymphoma]] - the most common gastric neoplasm | + | * [[Stomach and Abomasum Proliferative - Pathology #Lymphoma|Lymphoma]] - the most common feline gastric neoplasm |
* Fribrosarcoma | * Fribrosarcoma | ||
* Plasmacytoma | * Plasmacytoma | ||
| Line 18: | Line 18: | ||
==Signalment== | ==Signalment== | ||
* Male dogs are more commonly affected than female: e.g male:female ratio in those with carcinoma 2.5:1 | * Male dogs are more commonly affected than female: e.g male:female ratio in those with carcinoma 2.5:1 | ||
| − | * Mean age of dogs with | + | * Mean age of dogs with carinomas - 8 years |
| − | * Cats with | + | * Cats with carcinomas - usually over 10 years |
| − | * Mean age of dogs with benign | + | * Mean age of dogs with benign tumours - 15 years |
==Description== | ==Description== | ||
| − | Aetiology largely idiopathic though long term ingestion of dietary carcinogens may have some responsibility. Long term administration of nitrosamines may cause carcinomas in dogs. In humans, | + | Aetiology largely idiopathic though long term ingestion of dietary carcinogens may have some responsibility. Long term administration of nitrosamines may also cause carcinomas in dogs. 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 not usually FeLV positive. |
| − | 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 | + | 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 | * Pyloric outflow obstruction | ||
| − | * Ischaemic necrosis - tumour plugs | + | * Ischaemic necrosis - where tumour plugs develop in the surrounding vasculature |
Leiomyosarcomas: rarely metastasise. | Leiomyosarcomas: rarely metastasise. | ||
| − | Lymphoma: may be limited to the stomach | + | Lymphoma: may be limited to the stomach, may affect lymph nodes and other abdominal organs or may be multicentric. |
| − | Plasmacytoma: frequently | + | Plasmacytoma: metastasis is frequently evident in local lymph nodes. |
==Diagnosis== | ==Diagnosis== | ||
===History and Clinical Signs=== | ===History and Clinical Signs=== | ||
| − | * May | + | * May be mild or non-specific early on in the disease process |
* Chronic vomiting - blood tinged/'coffee grounds' appearance (partially digested blood) | * Chronic vomiting - blood tinged/'coffee grounds' appearance (partially digested blood) | ||
* Weight loss | * Weight loss | ||
| Line 47: | Line 47: | ||
* Electrolyte disturbances - secondary to vomiting | * Electrolyte disturbances - secondary to vomiting | ||
* Elevated BUN and creatinine - due to dehydration | * Elevated BUN and creatinine - due to dehydration | ||
| − | * Elevated hepatic enzymes - if hepatic metastasis has occured or if there is | + | * Elevated hepatic enzymes - if hepatic metastasis has occured or if there is obstruction to the common bile duct. |
===Positive Contrast Radiography=== | ===Positive Contrast Radiography=== | ||
| Line 58: | Line 58: | ||
* Loss of rugal folds | * Loss of rugal folds | ||
| − | ===Ultrasonography=== | + | ===Ultrasonography and Biopsy=== |
| − | Characteristic features of gastric neoplasia are a thickened gastric wall along with disruption of the wall layers. Enlarged lymph nodes may be observed. The rest of the abdominal organs should be checked for metastases. Ulceration appears as a | + | Characteristic features of gastric neoplasia are a thickened gastric wall along with disruption of the wall layers. Enlarged lymph nodes may be observed. The rest of the abdominal organs should be checked for metastases. Ulceration appears as a localised outpouching of the luminal (inner) surface with trapped gas bubbles. Definitive diagnosis requires histopathology of samples. Guided fine-needle or core biopsies may be taken at this time. |
===Endoscopy and Biopsy=== | ===Endoscopy and Biopsy=== | ||
| − | This allows direct visualisation of the lesion | + | This allows direct visualisation of the lesion. Several biopsies can be taken via grab biopsy, however the samples may be unrepresentative. |
===Surgical Biopsy=== | ===Surgical Biopsy=== | ||
| − | Alternatively, biopsies can be taken via gastrotomy at the time of surgical treatment (see below). If a GIST is susptected a CD117 immunohistochemical stain can be used for diagnosis. | + | Alternatively, biopsies can be taken via gastrotomy at the time of surgical treatment (see below). If a GIST is susptected a CD117 immunohistochemical stain can be used for diagnosis (in half of all dogs affected GIST tumours express CD117 (c-kit), a tyrosine kinase receptor). |
===Paraneoplastic Syndromes=== | ===Paraneoplastic Syndromes=== | ||
| Line 73: | Line 73: | ||
==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 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, there are | + | 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 on 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 injury to the local blood supply as well as the pancreas and extrahepatic biliary system. Post-operative complications are more frequent with resections associated with the pylorus. Neoplasia associated with the lesser curvature is generally unresectable. |
===Chemotherapy=== | ===Chemotherapy=== | ||
| Line 82: | Line 82: | ||
===Other Medical Management=== | ===Other Medical Management=== | ||
| − | Symptomatic therapy of for example vomiting may improve quality of life in the short term | + | 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. Inhibitors of c-Kit e.g imatinib have been used in humans with GIST tumours. Such inhibitors may be useful for GIST in animals. |
==Prognosis== | ==Prognosis== | ||
Revision as of 12:06, 11 August 2009
 |
This article is still under construction. |
More frequent compared with oesophageal neoplasia but still uncommon accounting for less than 1% of all malignancies. Malignant tumours include:
- Adenocarcinoma - 70-80% of all canine gastric neoplasms
- Squamous Cell Carcinoma
- Lymphoma - the most common feline gastric neoplasm
- Fribrosarcoma
- Plasmacytoma
- Leiomyosarcoma
- Mast cell
- Gastrointestinal stromal tumours (GIST tumours) - 20% of these tumours occur in the canine stomach
Benign tumours include:
- Polyps
- Leiomyoma
Signalment
- Male dogs are more commonly affected than female: e.g male:female ratio in those with carcinoma 2.5:1
- Mean age of dogs with carinomas - 8 years
- Cats with carcinomas - usually over 10 years
- Mean age of dogs with benign tumours - 15 years
Description
Aetiology largely idiopathic though long term ingestion of dietary carcinogens may have some responsibility. Long term administration of nitrosamines may also cause carcinomas in dogs. 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 not usually FeLV positive.
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
- Ischaemic necrosis - where tumour plugs develop in the surrounding vasculature
Leiomyosarcomas: rarely metastasise. Lymphoma: may be limited to the stomach, may affect lymph nodes and other abdominal organs or may be multicentric. Plasmacytoma: metastasis is frequently evident in local lymph nodes.
Diagnosis
History and Clinical Signs
- May be mild or non-specific early on in the disease process
- Chronic vomiting - blood tinged/'coffee grounds' appearance (partially digested blood)
- Weight loss
- Anorexia
- Maleana/occult faecal blood
- Anterior abdominal pain may or may not be present
Haematology and biochemistry
- Regerative anaemia - on account of gastric haemorrhage
- Electrolyte disturbances - secondary to vomiting
- Elevated BUN and creatinine - due to dehydration
- Elevated hepatic enzymes - if hepatic metastasis has occured or if there is obstruction to the common bile duct.
Positive Contrast Radiography
The following abnormalities may be observed:
- Apparent mass extending into the gastric lumen
- Delayed gastric emptying
- Changes in motility in certain areas of the stomach
- Thickening of the gastric wall or ulceration
- Filling defects
- Loss of rugal folds
Ultrasonography and Biopsy
Characteristic features of gastric neoplasia are a thickened gastric wall along with disruption of the wall layers. Enlarged lymph nodes may be observed. The rest of the abdominal organs should be checked for metastases. Ulceration appears as a localised outpouching of the luminal (inner) surface with trapped gas bubbles. Definitive diagnosis requires histopathology of samples. Guided fine-needle or core biopsies may be taken at this time.
Endoscopy and Biopsy
This allows direct visualisation of the lesion. Several biopsies can be taken via grab biopsy, however the samples may be unrepresentative.
Surgical Biopsy
Alternatively, biopsies can be taken via gastrotomy at the time of surgical treatment (see below). If a GIST is susptected a CD117 immunohistochemical stain can be used for diagnosis (in half of all dogs affected GIST tumours express CD117 (c-kit), a tyrosine kinase receptor).
Paraneoplastic Syndromes
- Hypercalcaemia - may be associated with lymphoma
- Hypoglycaemia - can be associated with leiomyomas and leiomyosarcomas and is potentially reversibe following tumour resection.
Treatment
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 on 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 injury to the local blood supply as well as the pancreas and extrahepatic biliary system. Post-operative complications are more frequent with resections associated with the pylorus. Neoplasia associated with the lesser curvature is generally unresectable.
Chemotherapy
For lymphoma only. There is an associated risk of gastric perforation.
Radiotherapy
Unreported. Surrounding tissues including the liver and intestine show poor tolerance.
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. Inhibitors of c-Kit e.g imatinib have been used in humans with GIST tumours. Such inhibitors may be useful for GIST in animals.
Prognosis
Variable:
- Benign tumours - Frequently cured by surgical resection. Prognosis good.
- Lymphoma - response to chemotherapy usually poor. Survival rates low.
- Most malignant tumours - usually 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.