Changes

==Description==

==Description==

A gastrinoma is a neoplasm of pancreatic islet cells that secretes the hormone gastrin, an example of a ectopic paraneoplastic disease.  The disease was first described by Zollinger and Ellison in humans in 1955 and it has since been recognised occasionally in dogs and cats.  Gastrinomas are the least common of the islet cell neoplasia, the other types being [[Glucagonoma|glucagonomas]] and [[Insulinoma|insulinomas]].  

A gastrinoma is a neoplasm of pancreatic islet cells that secretes the hormone gastrin, an example of an ectopic paraneoplastic disease.  The disease was first described by Zollinger and Ellison in humans in 1955 and it has since been recognised occasionally in dogs and cats.  Gastrinomas are the least common of the islet cell neoplasia, the other types being [[Glucagonoma|glucagonomas]] and [[Insulinoma|insulinomas]].  

The excessive secretion of gastrin leads to hypertrophy of the antral gastric mucosa and hyperstimulation of gastric acid production from the [[Stomach and Abomasum - Anatomy & Physiology|parietal cells]] of the stomach.  Antral hypertrophy may result in '''gastric outflow obstruction'''.  The excessive secretion of gastric acid leads to [[Gastric Ulceration - Dog|'''gastro-duodenal ulceration''']] and [[Oesophagitis|'''oesophagitis''']] due to gastro-oesophageal reflux.  In severe cases of the disease, deep gastric ulcers may erode blood vessels causing '''haemorrhage''' or perforate, causing septic [[Peritonitis - Cats and Dogs|'''peritonitis''']].  Gastrinomas have often metastasised to local lymph nodes or to the liver at the time of diagnosis.   

The excessive secretion of gastrin leads to hyperplasia of the crypt cells of the antral gastric mucosa and hyperstimulation of gastric acid production from the [[Stomach and Abomasum - Anatomy & Physiology|parietal cells]] of the stomach.  Antral hyperplasia may result in '''gastric outflow obstruction'''.  The excessive secretion of gastric acid leads to [[Gastric Ulceration - Dog|'''gastro-duodenal ulceration''']] and [[Oesophagitis|'''oesophagitis''']] due to gastro-oesophageal reflux.  In severe cases of the disease, deep gastric ulcers may erode blood vessels causing '''haemorrhage''' or perforate, causing septic [[Peritonitis - Cats and Dogs|'''peritonitis''']].  Gastrinomas have often metastasised to local lymph nodes or to the liver at the time of diagnosis.   

==Signalment==

==Signalment==

===Laboratory Tests===

===Laboratory Tests===

====Haematology====

====Haematology====

If haemorrhage is occurring, the '''packed cell volume''' (PCV) and blood '''haemoglobin''' concentration may be abnormally low and there may be signs of regeneration after 48-72 hours.  In cases of chronic haemorrhage, the blood urea concentration may be raised and, as '''iron''' reserves are expended, a microcytic hypochromic anaemia may develop.

If haemorrhage is occurring, the '''packed cell volume''' (PCV) and blood '''haemoglobin''' concentration may be abnormally low and there may be signs of regeneration after 48-72 hours.  In cases of chronic haemorrhage, the blood [[Urea|urea]] concentration may be raised and, as '''iron''' reserves are expended, a microcytic hypochromic anaemia may develop.

Areas of gastro-duodenal ulceration will be inflamed, producing a '''leucoytosis'''.  This may be neutrophilic, monocytic or both depending on the stage of disease.

Areas of gastro-duodenal ulceration will be inflamed, producing a '''leucoytosis'''.  This may be neutrophilic, monocytic or both depending on the stage of disease.

'''Ultrasonography''' is most useful for detection of gastro-duodenal ulceration and of metastases in the liver and local lymph nodes.

'''Ultrasonography''' is most useful for detection of gastro-duodenal ulceration and of metastases in the liver and local lymph nodes.

Ulceration and antral hypertrophy may also be visualised by '''endoscopy'''.

Ulceration and antral hyperplasia may also be visualised by '''endoscopy'''.

===Other Tests===

===Other Tests===