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| − | ===Pituitary Neoplasia=== | + | ===[[Pituitary Neoplasia]]=== |
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| − | Tumours within the pituitary fossa may be functional and sectrete trophic factors. However, more commonly they are non-functional and are space-occupying lesions.
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| − | Pressure on neighbouring structures causes clinical signs, for example:
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| − | *Pressure on the optic chiasma produces ocular signs.
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| − | *Pressure on the hypothalamus may lead to [[Frohlich's Adiposogenital Syndrome - Pathology|Frohlich's adiposogenital syndrome]].
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| − | *Pressure on the neurohyposphysis may lead to failure of ADH secretion. This will allow large volumes of water to be lost form the kidney; [[Diabetes Insipidus]].
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| − | [[Image:Pituitary tumour.jpg|right|thumb|125px|<small><center>'''Pituitary neoplasia'''. Courtesy of A. Jefferies</center></small>]]
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| − | Neoplasia may be derived from:
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| − | *Pituitary itself.
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| − | *Surrounding brain tissue.
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| − | *Ependyma.
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| − | ====Pituitary neoplasia in the horse====
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| − | Neoplasia usually occurs in the ''pars intermedia'' of the anterior pituitary and compresses the hypothalamus.
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| − | ''Clinical signs'':
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| − | *Polyuria and polydipsia.
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| − | *Increased appetite reulting in increased food intake and downregulation of insulin receptors. This leads to a hyperglycaemia.
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| − | *Somnolence.
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| − | *Muscle wekaness.
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| − | *Hirsutism.
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| − | *Hyperhidrosis.
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| − | [[Category:Pituitary Gland - Pathology]]
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| − | [[Category:Neoplasia]]
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Revision as of 13:48, 21 February 2011
Anatomy and Physiology
Anatomy and Physiology of the pituitary gland can be found here.
General Pathological Principles
Two major changes can occur in an endocrine gland:
- Failure of hormone production:
- Destruction or lack of cells.
- Lack of trophic drive.
- Overproduction of hormone:
- Hyperplasia or neoplasia.
- Excessive trophic drive.
Pituitary Hypofunction
Pituitary Hyperfunction
Gigantism