Pathology of the pituitary gland Flashcards
Which lobe of the pituitary is more vascularized and why? This confers what kind of susceptibility?
Anterior- distribution of hormones
Posterioris more neuronal in nature.
Therefore, the anterior lobe is more likely to suffer with profound hypotension.
3 cell types of the pars distalis
chromophobes, acidophils, basophils
T or F All granules secreted from the anterior pituitary, no matter the hormone, are the same size.
False. There is some correlation between size of granule and hormone secreted
What color are basophils?
blue
Embryological development of ant pit?#
Develop from invagination of oral ectoderm call ed pouch of Rathke.
Embryological development of post pit#
Forms from neuroectoderm derived from hypothalamus. Fuses with pouch of rathke.
Causes of hypopituitarism? Which of these is most common?
Surgery, radiation, cysts, tumors, ischemia/hemorrhage, inflammation, empty sella syndrome, gene defect
Tumor is most common, most commonly adenoma
About ____% of anterior lobe must be lost for symptoms to occur post infarction.
75– We have more endocrine capacity than we need
Which lobe is usually affected by infarction?
Anterior
There is damage to the pituitary stalk affected anterior and posterior pituitary. What is the only hormone that will have increased secretion?#
Prolactin
Causes of pituitary infarction
DM, CVA, ICP, hypoperfusion of any cause, sheehan’s, pituitary apoplexy
What is pituitary apoplexy?#
Sudden hemorrhage into the gland usually due to adenoma
Histologically, what will infarct of the pituitary look like?
Loss of nuclei, ghost cells
How can pituitary adenomas cause hypopituitarism?#
mass effect or pituitary apoplexy
What happens to the pituitary gland in pregnancy?#
doubles in size without a significant increase in blood supply
What inflammatory lesions can cause pituitary damage?
Acute inflammation (sinusitis, osteomyelitis), granulomatous (TB, fungal, sarcroid, idiopathic giant cell granuloma), lymphocytic (autoimmune)
Granulomas tend to affect the _____.
skull base (pituitary)
Describe sarcoidosis affecting the pituitary.
Rule of TB. Tx with steroids. #Look for Shaumann bodies and asteroid bodies withing giant cells. Remember GRAIN (gammaglobulinemia, RF, ACE increase, Interstitial fibrosis, Noncaseating granuloma). Produce elevated 1,25 (OH2)VD--> hypercalciuria +/- hypercalcemia
Things causing hyperpituitarism
hyperplasia, pituitary adenoma, ectopic secretion, hypothalamic disorder
Is pituitary hyperplasia common?
No
Addison’s is an example of ____ hyperplasia.
ACTH
Pituitary adenomas make up ___% of intracranial neoplasms.
10
What age groups sees more pituitary adenomas?
30-50
Are pituitary adenomas usually isolated or associated with other syndromes?
Usually isolated
What kind of pituitary adenomas are detected early on?
Functioning
What symptoms are caused by pituitary adenoma mass effect?#
bitemporal hemianopsia, hypopituitarism, headache
Most common functional pituitary adenoma
prolactin adenoma
Histopathology of pituitary adenoma
Sheet like growth pattern, relative monomorphism, loss of typical reticular fiber network, functional status cannot be predicted from histo appearance, immunohistochemical stain can be confirmatory
What is a craniopharygioma?#
Congenital tumor arising from remnants of Rathke pouch. Most common cause of hypopituitarism in children.
What does craniopharyngioma look like histologically? (wiki)
nesting squamous epithelium, calcium deposits, cystic spaces. Can be papillary or adamantinomatous,
