Pituitary adenoma pathophysiology: Difference between revisions
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__NOTOC__ | __NOTOC__ | ||
{{Pituitary adenoma}} | {{Pituitary adenoma}} | ||
{{CMG}} {{AE}} {{AAM}} | |||
==Overview== | |||
==Pathophysiology== | |||
*Over half of all adenomas are secretory | |||
*Although even when this is the case this may not be the cause of presentation. | |||
*Larger adenoma can lead to hormonal imbalance due to mass effect rather than secretion. | |||
*Hypopituitarism or moderately elevated prolactin are both seen, the later due to stalk effect; prolactin release (unlike other pituitary hormones) is tonically inhibited by prolactin inhibitory hormone (a.k.a. dopamine) and as such compression of the pituitary infundibulum can result in elevation of systemic prolactin levels due to interruption of normal inhibition. | |||
*Most of the cases presenting due to mass effect are due to non-secreting macroadenomas and the most common structure to be compressed by a macroadenoma is the [[optic chiasm]]. | |||
*Invasion into the [[cavernous sinus]] is also encountered, with occasional compression of the [[oculomotor]] (CN III) or, less frequently [[abducens]] (CN VI) nerves. Uncommonly large tumours may result in hydrocephalus (by compressing the midbrain or distorting the third ventricle), orbital or sinonasal symptoms. | |||
==References== | ==References== | ||
Revision as of 14:07, 29 September 2015
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Ahmad Al Maradni, M.D. [2]
Overview
Pathophysiology
- Over half of all adenomas are secretory
- Although even when this is the case this may not be the cause of presentation.
- Larger adenoma can lead to hormonal imbalance due to mass effect rather than secretion.
- Hypopituitarism or moderately elevated prolactin are both seen, the later due to stalk effect; prolactin release (unlike other pituitary hormones) is tonically inhibited by prolactin inhibitory hormone (a.k.a. dopamine) and as such compression of the pituitary infundibulum can result in elevation of systemic prolactin levels due to interruption of normal inhibition.
- Most of the cases presenting due to mass effect are due to non-secreting macroadenomas and the most common structure to be compressed by a macroadenoma is the optic chiasm.
- Invasion into the cavernous sinus is also encountered, with occasional compression of the oculomotor (CN III) or, less frequently abducens (CN VI) nerves. Uncommonly large tumours may result in hydrocephalus (by compressing the midbrain or distorting the third ventricle), orbital or sinonasal symptoms.