Pituitary Gland Path Flashcards
What inhibits ADH release
states of hypervolemia and increased atrial distention
describe the histological array of cells in the anterior pituitary
- eosinophilic cytoplasm (acidophil)
- basophilic cytoplasm (basophil)
- poorly staining cytoplasm (chromophobe)
Most common cause of hyperpituitarism
adenoma of anterior pituitary
4 causative genes that have been identified in adenomas
- MEN1
- CDKN1B
- PRKAR1A
- AIP
what is the most common form of clinically significant ischemic necrosis of the anterior pituitary
-Sheehan syndrome, also known as postpartum necrosis
What are the clinical symptoms of Nelson syndrome
- Hypercortisolism does NOT develop
- patients present with mass effects due to the pituitary tumors
- can be hyperpigmentation because of the stimulatory effect of other products of the ACTH precursor molecule on melanocytes
are most pituitary carcinomas functional or not?
functional
What is one of the most common alterations in pituitary adenomas
G protein
Acidophil lactotroph adenomas are rare. these are called what? and characterized by what?
- densely granulated lactotroph adenoma
- diffuse cytoplasmic PIT-1 expression localization
What do patients with craniopharyngioma generally come to attention with
- headaches and visual disturbances
- children sometimes growth retardation
difference in the 2 types of craniopharyngiomas radiographically
- Adamantinomatous: frequently contains calcifications
- papillary: rarely calcifies
histology of papillary craniopharyngiomas
- both solid sheets and papillae lined by well-differentiated squamous epithelium
- lack keratin, calcifications, and cysts
- the squamous cells of the solid sections lack the peripheral palisading
- do NOT typically generate a spongy reticulum in internal layers
size of corticotroph adenomas
usually microadenomas
Somatotroph adenoma causes what in children?
adults?
- gigantism
- acromegaly
Average size of craniopharyngioma
3-4 cm
What is the most common hormone deficiency found in gonadotroph adenomas?
what does this deficiency cause?
- LH
- decreased energy and libido in men
- amenorrhea in PREmenopausal women
What factors are required for gonadotroph differentiation?
SF-1 and GATA-2
What are the 2 distinct histological variants of craniopharyngioma
- Adamantinomatous (children)
- Papillary (adults)
approximately 40% of somatotroph cell adenoma bear what mutations
GNAS that abrogate the GTPase activity of Gsa, leading to constitutive activation of Gsa, persistent generation of cAMP, and unchecked cellular proliferation
How do larger craniopharyngiomas impact prognosis
-they are more invasive but this does NOT impact prognosis
Excess production of ACTH by functioning corticotroph adenomas leads to what?
adrenal hypersecretion of cortisol and the development of hypercortisolism . . . Cushing SYNDROME
age distribution of craniopharyngioma
- bimodal
- childhood (5-15)
- adults 65 or older
General causes of hypopituitarism
- destructive processes like:
- ischemia
- surgery
- radiation
- inflammation
- non-functional pituitary adenoma
Some pituitary adenoma can secrete 2 hormones, what the most common combo?
GH and prolactin