Hypopituitarism

Introduction

• 95% due to pituitary adenomas
• Other causes include:
  • Tumors
  • Inflammatory/infectious pituitary destruction
  • Irradiation
  • Sheehan’s
  • TBI
  • SAH

Presentation

• Combined deficiencies of some (rarely all) of TSH, ACTH, GH, FSH, LH, oxytocin, prolactin and ADH
• Often present pale (lack of MSH secondary to ACTH deficiency) with secondary adrenal insufficiency (cortisol deficient but NOT aldosterone deficient – hence not hyperkalaemic)
• May still be hyponatraemic but this is due to cortisol deficiency with subsequent SIADH rather than aldosterone deficiency

ACTH deficiency

• Symptoms almost exclusively those of cortisol deficiency
• Do not lack aldosterone so not hyperkalaemic
• Does not result in hyperpigmentation unlike primary adrenal insufficiency

Gonadotropins

• Women
  • Ovarian hypofunction, reduced oestradiol release
  • Irregular periods/amenorrhoea, anovulatory infertility, hot flashes, vaginal atrophy
• Men
  • Testicular hypofunction
  • Reduced energy and libido, hot flashes

Growth hormone

• In children leads to short stature
• In adults get increased fat mass, reduced muscle mass, impaired QoL and increased mortality

Prolactin

• Inability to lactate after delivery

Treatment

• Hydrocortisone 250mg IV stat then 100mg QID
• IV T4 4mcg/kg stat
• Correct electrolyte disturbance
• Treat underlying cause

Last Updated on October 6, 2021 by Andrew Crofton