SFP: pituitary pathology II Flashcards
What is Cushing’s disease?
A pituitary tumor releasing ACTH causes the adrenal glands to make too much cortisol.
What are clinical signs of Cushing’s disease?
Bruising, enhanced stretch marks, truncal obesity/thin limbs, moon facies, poor wound healing, buffalo hump, flushing.
What will a high-dose dexamethasone suppression test show with Cushing’s disease?
It will cause suppressed cortisol production! This only happens in pituitary causes of hypercortisolemia.
What happens to plasma ACTH in Cushing’s disease?
It’s way up.
What is Crooke cell change?
When there is too much cortisol, ACTH producing cells in the pituitary gain extra purple staining, which is an adaptation to attempt to reduce ACTH production.
What is true of anterior pituitary tumors in terms of location?
They tend to break out of the bone and invade. They often invade respiratory mucosa. This does not indicate malignancy.
What are clinical signs of gonadotroph adenomas?
Decreased libido, amenorrhea, headaches.
What are null cell adenomas?
Pituitary adenomas that don’t produce excess hormone. They have lots of mitochondria, few secretory granules, and often present with mass effect.
What are thyrotroph adenomas?
Pituitary adenoma producing TSH and causing hyperthyroidism.
What are Rathke cleft cysts?
Cysts lined with respiratory mucosa found between anterior pituitary and posterior pituitary.
What are craniopharyngiomas?
Solid, cystic tumors filled with dark oil-looking substance found in the anterior pituitary.
What is the histology of craniopharyngioma?
Squamous lining, visible keratin, and calcifications.
What can sarcoidosis do to the pituitary?
Hyposecretion of anterior pituitary hormones.
What is empty Sella syndrome?
Pressure put on the anterior pituitary compresses it and causes stalk effect.
How do we evaluate for GH deficiency?
Should show inadequate response to two of the following provocative tests: 1. Insulin-induced hypoglycemia 2. Exercise 3. Arginine 4. L-dopa.
What is central diabetes insipidus?
Damage, idiopathic, or familial causes that lowers secretion of ADH from the posterior pituitary.
What are inflammatory causes of central diabetes insipidus?
Langerhans cell histiocytosis and sarcoidosis.
What are clinical symptoms of central diabetes insipidus?
Polyuria, polydipsia, nocturia, shock/hypertonic encephalopathy.
How do we test for central diabetes insipidus?
Test ADH level, high serum osmolality, low urine osmolality.
What is SIADH?
Excess secretion of ADH from the posterior pituitary.
What are clinical signs of SIADH?
Hypotonic serum, volume expansion, hypertonic urine, cerebral edema and associated symptoms, seizures.
What are some causes of SIADH?
Stress, pain, surgery, paraneoplastic syndromes, meds.
What is the most common paraneoplastic cause of SIADH?
Small cell carcinoma of the lung (secretes ADH).
What are lab signs of SIADH?
Low serum osmolality, high urine osmolality, high serum ADH.
