Hypopituitarism

Question 1

Causes of hypopituitarism

Answer 1

• Most common are tumors (macro adenomas)
• Surgery, radiation on pituitary
• Infarction/hemorrhage: sheehan syndrome, apoplexy
• Trauma
• Inflammatory d/o: histiocytosis, sarcoid, lymphocytic hypophysitis, hemochromatosis
• Infection: TB, fungal
• Genetic deficiencies
• Hypothalamic diseases: craniopharyngioma, rathke’s cleft cyst, infection, trauma, tumor, etc

Question 2

Various etiologies of hypopit

Answer 2

• Pituitary apoplexy: sudden hemorrhage resulting in severe headache, diplopia, and hypopit
• Sheenan syndrome: post partum hemorrhage and infarction of pit
• Lymphocytic hypophysitis: autoimmune inflammation of pit
• Congenital: abnormal genes that are involved in differentiating precursor ant pituitary cells into GH, prolactin, TSH cells
• Empty sella syndrome: either due to apoplexy or defect in the sella leading to CSF entry and enlargement

Question 3

Clinical features of hypopit

Answer 3

• GH deficiency: fatigue, decreased muscle strength
• LH/FSH: sexual dysfunction, infertility, fatigue, anemia (testosterone stimulates EPO)
• ACTH: weakness, weight loss, hypotension
• TSH: fatigue, cold intolerance, weakness, anemia
• Prolactin: inability to lactate

Question 4

Craniopharyngiomas and rathke’s cleft cyst

Answer 4

• Both from remnants of ectoderm of rathke’s pouch
• Craniopharyngiomas have more serious clinical consequences: visual and hormonal abnormalities
• Rathke’s cysts are more benign but can show pressure effects
• Rathke’s cysts hormonal abnormalities are usually only GH and gonadotropin deficiencies

Question 5

Gonadotropin deficiency and Rx 1

Answer 5

• Premenopausal women: oligo or amenorrhea, infertility, menopausal Sx (hot flashes, vaginal dryness), breast atrophy, loss of bone density
• Post menopausal women generally are ASx
• Men: infertility, decreased libido, fatigue due to anemia from low T levels
• Labs: use estradiol and testosterone levels, and compare to serum LH
• 1o hypogonadism will have low estradiol/T and high gonadotroph levels

Question 6

Gonadotropin deficiency and Rx 2

Answer 6

• Gonadotropin deficiency (2o) will have low estradiol/T and low or inappropriately nl gonadotroph levels
• Estradiol levels in postmenopausal women serve no purpose; check FSH levels and they should be high (if nl there is deficiency)
• Rx depends on if the pt is infertile and wants children
• If they do not want children, give estrogen-progestins to women and testosterone to men
• If they do want children Rx the women w/ gonadotrophs (LH/FSH) or GnRH depending on where the deficit is

Question 7

Growth hormone deficiency

Answer 7

• In children it causes failure to grown, in adults Sxs are vague
• Adults: fatigue, decreased feeling of well-being, decrease exercise tolerance, smooth skin, disproportionate amount of abdominal fat, decreased muscle mass
• GH decreases bone density, life expectancy and increases CV disease risk
• Labs: IGF and GH levels are not sufficient, must do insulin tolerance test (induce hypoglycemia) and see 5ng/ml increase in GH or do IV arginine infusion and see 5ng/ml increase in GH
• hGH replacement for children w/ GH deficiencies, may be used in some adults w/ symptomatic GH deficiency

Question 8

ACTH deficiency

Answer 8

• Have most Sxs of hypoadrenalism, many are mild but when faced w/ stress or illness they can get worse quickly
• Sx include fatigue, weakness, low BP
• Important to note hypoadrenalism from hypothalamus/pituitary does not produce hyper pigmentation, hyperkalemia, or sodium wasting as 1o hypoadrenalism does
• Labs: am cortisol >15 means normal function, <3 means cortisol deficient, and btwn 3-15 means must do further (stimulation) tests
• Rx of ACTH deficiency is GCCs (first: hydrocortisone)
• Remember: if pt gets sick must double dose and come into hospital (always wear bracelet)

Question 9

TSH deficiency

Answer 9

• Sx of hypothyroidism: aches and pains, fatigue, depression, trouble concentrating, modest weight gain, constipation, cold intolerance, increased sleeping, yellow/cool/dry skin, mild HTN, delayed return of DTRs, bradycardia, muscle weakness
• Labs: measure FT4 and TSH
• If FT4 is low and TSH is inappropriately nl or low-> hypothal/pit problem (2o)
• FT4 low and TSH high-> thyroid problem
• Rx: LT4 replacement, goal is FT4 to be in upper 1/2 of nl range

Question 10

Prolactin deficiency

Answer 10

-Not done since there is no Rx