Difference between revisions of "Insulinoma"
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==Description== | ==Description== | ||
| − | Insulinomas are well slow growing, encapsulated, functional tumours of the beta cells of the pancreatic islet cells, They secrete inaappropriately high amount of insulin irrespective of the serum glucose level. They are predominantly malignant (90% of canine isulinomas), with a high metastatic rate to regional lymph nodes, liver and omentum. | + | Insulinomas are well slow growing, encapsulated, functional tumours of the beta cells of the pancreatic islet cells, They secrete inaappropriately high amount of insulin irrespective of the serum glucose level. They are predominantly malignant (90% of canine isulinomas), with a high metastatic rate to regional lymph nodes, liver and omentum. 60% of isulinomas are carcinomas, which are more likely to be endocrinologically active, the others being adenomas. |
| Line 30: | Line 30: | ||
*mentally dull and disorientated | *mentally dull and disorientated | ||
| − | These sigs may be intermittent at the beginning of the disease, but this becomes progressively more often. In between hypoglycaemic episodes, the animals are normal. A presumptive diagnosis can be made on the demonstration of the Wipple's triad. This includes presence of clinical signs associated with hypoglycaemia, fasting hypoglycaemia and amelioration of clinical signs with the admistration of glucose. | + | These sigs may be intermittent at the beginning of the disease, but this becomes progressively more often. In between hypoglycaemic episodes, the animals are normal. A presumptive diagnosis can be made on the demonstration of the Wipple's triad. This includes presence of clinical signs associated with hypoglycaemia, fasting hypoglycaemia and amelioration of clinical signs with the admistration of glucose. Insulinoma should be considered especially when clinical signs are associated with exercise, extended fasting or after feeding. |
| Line 38: | Line 38: | ||
====Other Tests==== | ====Other Tests==== | ||
| − | * | + | *A tentative diagnosis can be made if inappropriately high serum insulin level in the presence of hypoglycaemia is shown. |
| + | |||
| + | ===Histopathology=== | ||
| + | This is needed to confirm the diagnosis. | ||
===Diagnostic Imaging=== | ===Diagnostic Imaging=== | ||
| Line 51: | Line 54: | ||
==Treatment== | ==Treatment== | ||
===Medical=== | ===Medical=== | ||
| − | This is more suitable to patients which | + | This is more suitable to patients in which surgery has been declined or when surgery is inappropriate or fails due to the presence of metastasis. |
| − | *Small and frequent meals (3-6 times/day) | + | *Small and frequent meals (3-6 times/day) of a simple carbohydrate content. |
*Exercise restriction. | *Exercise restriction. | ||
*Lowest possible dose of glucocorticoid given to increase hepatic glucose prodection and decrease cellular glucose uptake. | *Lowest possible dose of glucocorticoid given to increase hepatic glucose prodection and decrease cellular glucose uptake. | ||
Revision as of 13:24, 20 August 2009
 |
This article is still under construction. |
Signalment
- More common in dogs than cats
- Middle-aged to older dogs
- No sex predilection
- Breed predisposition, more common in medium to large-breed dogs:
- Irish Setter
- German Shepherd
- Labrador Retriever
- Standard Poodle
- Boxer
Description
Insulinomas are well slow growing, encapsulated, functional tumours of the beta cells of the pancreatic islet cells, They secrete inaappropriately high amount of insulin irrespective of the serum glucose level. They are predominantly malignant (90% of canine isulinomas), with a high metastatic rate to regional lymph nodes, liver and omentum. 60% of isulinomas are carcinomas, which are more likely to be endocrinologically active, the others being adenomas.
Diagnosis
Clinical Signs
The following signs are attributal to hypoglycaemia:
- collapse
- muscle tremor
- muscle weakness
- ataxia
- mentally dull and disorientated
These sigs may be intermittent at the beginning of the disease, but this becomes progressively more often. In between hypoglycaemic episodes, the animals are normal. A presumptive diagnosis can be made on the demonstration of the Wipple's triad. This includes presence of clinical signs associated with hypoglycaemia, fasting hypoglycaemia and amelioration of clinical signs with the admistration of glucose. Insulinoma should be considered especially when clinical signs are associated with exercise, extended fasting or after feeding.
Laboratory Tests
Biochemistry
- Hypoglycemia
Other Tests
- A tentative diagnosis can be made if inappropriately high serum insulin level in the presence of hypoglycaemia is shown.
Histopathology
This is needed to confirm the diagnosis.
Diagnostic Imaging
Radiography
A thoracic radiograph may be used to identify any pulmonary metastases, but this is uncommon.
Ultrasonography
Occasionally, it may be possible to visualise the location of the tumour on the pancreas. However, this may not be possible if the tumous is too small. Metastases to lymph nodes and liver can sometimes be revealed.
Treatment
Medical
This is more suitable to patients in which surgery has been declined or when surgery is inappropriate or fails due to the presence of metastasis.
- Small and frequent meals (3-6 times/day) of a simple carbohydrate content.
- Exercise restriction.
- Lowest possible dose of glucocorticoid given to increase hepatic glucose prodection and decrease cellular glucose uptake.
Surgery
A partial pancreatectomy is suitable for patients with a solitary tumour, provided there is no metastasis.
Prognosis
References
- Ettinger, S.J. and Feldman, E. C. (2000) Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition) W.B. Saunders Company.
- Fossum, T. W. et. al. (2007) Small Animal Surgery (Third Edition) Mosby Elsevier
- Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier.