Hypopituitarism - Manifestations

Symptoms depends on rapidity of disease (i.e. pituitary aploplexy --> sudden onset, vs radiation-induced dysfunction – slower), as well as severity of deficiency (partial vs complete) and what types of cells are affected.

6 Hormones Secreted by the Pituitary and their associated symptoms in deficient states:
1. ACTH – deficiency leads to secondary adrenal insufficiency, which can present as hypotension, malaise, weakness, fatigue, anorexia, GI upset, altered mental status.  As opposed to primary AI, should not have aldosterone deficiency so will not see the salt wasting and hyperkalemia, and also will not have the hyperpigmentation that goes with primary AI.
2. TSH – central hypothyroidism, which can present in extreme state with myxedema coma à altered mental status, hypothermia, hypotension, bradycardia, hyponatremia, hypoglycemia, and CHF/cardiogenic shock!
3. Prolactin – presents as inability to lactate
4. Growth Hormone – increased risk of osteoporosis, and fatigue
5. FSH/LH – oligo/amenorrhea and infertility
6. ADH – (secreted by hypothalamus and released by posterior pituitary) – deficiency causes diabetes insipidus

Clearly, the immediately life-threatening manifestations are the adrenal insufficiency and hypothyroidism/myxedema coma, whereas you do not worry about the other ones acutely.  Remember, if treating hypopituitarism with myxedema coma and adrenal insufficiency, always treat with steroids first before IV thyroid hormone, otherwise can precipitate an adrenal crisis (common boards question).

(Chanu Rhee MD, 11/30/10)