A 75-year-old woman presented with general fatigue progressing to somnolence. Laboratory
tests showed marked hyponatremia, TSH in the normal range, but low levels of free
T3 and free T4. Evaluation of pituitary hormones and magnetic resonance imaging of
the pituitary unmasked findings characteristic for hypophysitis with secondary adrenal
insufficiency and secondary hypothyroidism. Hormonal substitution with hydrocortisone
and levothyroxine resulted in rapid improvement of all symptoms and signs. Without
additional treatment shrinkage of the pituitary gland could be documented. Our report
extends the known clinical and pathological spectrum of hypophysitis and illustrates
the need to include this uncommon entity in the differential diagnosis of hyponatremia
even in elderly patients.
Hypophysitis - hyponatremia - hypopituitarism