Pituitary 2 Flashcards
What syndrome can corticotroph adenoma lead to?
Cushing syndrome
Are corticotroph adenomas densely or sparsely granulated and what do both variants stain positive for and why?
Most are densely.
Stain for PAS because of POMC.
What is the correct way to define Cushing’s disease?
When the high cortisol levels are due to excessive ACTH by the pituitary
How do we correctly define Cushing syndrome?
High cortisol levels and all the signs and symptoms that come along with it
Two common underlying cancers of Cushing syndrome?
Small cell carcinoma of lung
Pancreatic carcinoma
What is the size of a micro adenoma of corticotrophs and macro adenoma of corticotrophs?
Less than 10 and greater than 10 mm
What is the most common cause of Cushing syndrome?
Glucocorticoid administration
What are the 4 main causes of cushing’s syndrome?
Exogenous steroids, cushings disease, adrenal cushings, and paraneoplastic Cushing
What is the result on the body with casings caused by exogenous steroids and the effect on CRH, ACTH, and Cortisol?
It is the exogenous steroids causing the effects that cortisol would cause. It has nothing to do with the HPA axis.
What is the result of cushings disease on the body?
The adenoma in the pituitary gland is secreting a ton of ACTH which is causing the production of a ton of cortisol.
What is the effect of adrenal cushings on the body?
The adrenal gland tumor is pumping out a ton of cortisol
What is the effect of the body of paraneoplastic tumor cushings?
Lung cancer is pumping out a ton of ACTH which causing the production of a ton of cortisol
What does it mean if we still have a high level of ACTH and cortisol after the low dose dexamethasone test?
It means the patient has Cushing’s syndrome because they are so used to having a ton of cortisol in the body so the small dose will not have any suppression effect on the HPA axis.
What will plasma cortisol, ACTH, cortisol level after low dose test, and cortisol level after high dose test be for Cushing disease?
High, high, not suppressed or high, suppressed or high
What will plasma cortisol, ACTH, cortisol level after low dose test, and cortisol level after high dose test be for ectopic source of ACTH?
High, high, not suppressed or high, not suppressed or high.
What will plasma cortisol, ACTH, cortisol level after low dose test, and cortisol level after high dose test be for adrenal cushing disease?
High, low, high or not suppressed, high or not suppressed
3 ways to treat corticotroph adenomas?
Surgery, dopamine agonists, somatostatin agonists
What is the classic clinical presentation of Nelson syndrome and what is the main problem?
Patients with cushings disease can have their adrenal glands removed. Sometimes these patients develop pituitary adenomas because they don’t have the negative feedback of the adrenals. Hyperpigmentation of the skin is the classic symptom.
Thyrotroph adenomas are a rare cause of what?
Hyperthyroidism
Earlier, I talked about GNAS being associated with pituitary adenomas. Explain how the mutations actually causes problems?
Mutation of the GNAS gene makes the alpha subunit lose its GTPase activity so we don’t get to GDP. Remember, GDP shuts off the signaling cascade.
3 characteristics she wants us to know about non aggressive adenomas?
Well circumscribed, can erode bone, and can bleed.
2 characteristics she wants us to know about aggressive adenomas?
Poorly circumscribed and can invade brain
What 2 products are most commonly secreted out of a pituitary carcinoma?
Prolactin and ACTH
What is an absolutely necessary condition for pituitary carcinoma?
Craniospinal or systemic metastasis
What is the USP8 mutation associated with?
Sporadic corticotroph adenoma
What is the AIP gene mutation associated with?
Inherited mutation that makes you a giant
What are the two hallmark symptoms of a lady with Sheehan syndrome?
Hypopituitarism and cant lactate
