Hypopituitarism in adults (Pan hpypopituitarism) its causes and newest treatment

Etiology :

a. Destruction of pituitary gland by :

i. Surgery → in ttt of Hyperfunction.

ii. Irradiation → in ttt of Hyperfunction.

iii. Tuberculosis, sarcoidosis, heamochromatosis.

b. Sheehan’s syndrome :

pituitary infarction after sever post-partum hge ?

c. Neoplasm : acidophil adenoma.

d. Trauma : fracture base of i skull.

e. Idiopathic : auto-immune.

3. C / P :

a. C / p of i cause :

i. Surgery.

ii. Irradiation.

iii. Sever post-partum bleeding.

b. C / p of i hormone :

According to i frequency of appearance, i following occur :

Gondotrophines & GH (2g) are lost early

then → TSH then → ACTH deficiency.

i. Gonadal deficiency :

1. ♀ : amenorrhea, loss of libido, infertility, loss of

pubic & axillary hair.

2. ♂ : impotence, loss of libido, infertility, loss of

pubic & axillary hair.

ii. GH deficiency :

No clinical manifestations in adult

1. skin wrinkling & weakness.

2. ↑↑ sensitivity to insulin ( hypoglycemia ).

iii. TSH deficiency :

_ result in hypothyroidism.

iv. ACTH deficiency :

Results in 2ry adrenal insufficiency it

simulates Addison’s disease except :

1. no pigmentation → absent ACTH.

2. no marked hypotension due to presence of

aldosterone.

N.B. :

aldosterone production is mainly dependant on i

renin- angiotensin system not on ACTH.

v. Coma :

Causes of coma :

1. hypoglycemic coma due to GH & cortisone.

2. myxoedema coma.

3. pressure in cases of pituitary tumors.

N.B. :

If i patient has associated DI & hyperprolactinaemia

the problem is at i hypothalamus.
4. Differential diagnosis 

a. From 1ry hypognadism : → high FSH.

b. From 1ry Addison’s disease :

i. skin pigmentation.

ii. high ACTH.

iii. marked hypotension.

c. From anorexia nervosa :

i. normal hair & breast.

ii. aggressive attitude.

iii. normal cortisol.

iv. high G.H. due to hypoglycemia.

d. From thyroid myxoedema : see later

5. Investigation :

a. Inv. for i cause :

i. Imaging for i gland :

1. X-ray : shows i sella tursica.

2. C.T. & M.R.I. → i best.

b. Assay of i hormone level :

1. ↓ G.H. [ normal = 1 – 5 n.gm/ml.] & ↓ IGF-1.

2. ↓ FSH, ↓ LH & ↓ sex hormones.

3. ↓ TSH, ↓ T3 & ↓ T4.

4. ↓ ACTH & ↓ cortisol.
c. Inv. of i function of i hormone :

1. hypoglycemia.

2. hyponatremia.

d. Stimulatory test :

stimulatory test → for Hypofunction.

_ material : insulin.

_ I.V. insulin followed by TRH & GnRH.

1. normal → ↓ blood sugar → marked

elevation of GH, TSH, FSH, LH & cortisol.

2. in pan-hypopituitarism : no change.

6. Treatment :

a. TTT of i cause.

b. Replacement therapy :

i. Hydrocortisone : dose : 30 mg/ day.

20 mg a.m. & 10 mg p.m.

ii. Gonadal hor.s : ♂ → testosterone.

♀ → estrogen/progesterone.

iii. Thyroxin : dose 0.1 – 0.2 mg/day.

given after steroid replacement.

iv. Recently :

1. purified pituitary hor.s.

2. hypothalamic releasing factors.
see the pictures