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Endocrine system




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A 38-year-old woman comes to the emergency department because of a severe headache and multiple episodes of non-bloody, non-bilious emesis for the past few hours. Review of systems is significant for fatigue, constipation, and problems with peripheral field vision for the past few months. Her last menstrual period was 4 months ago. Temperature is 37.0°C (98.6°F), pulse is 58/min, respirations are 10/min, and blood pressure is 92/64 mm Hg. Physical examination shows a lethargic female complaining of severe pain. Visual field is tunneled with doubling of vision. Head magnetic resonance imaging is shown below:

Reproduced from: Wikimedia Commons

Which of the following is the most likely diagnosis?

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Bitemporal hemianopia p. 562

hypopituitarism as cause p. 345

Brain injury

hypopituitarism from p. 345


hypopituitarism p. 345

Craniopharyngiomas p. 546, 637

hypopituitarism with p. 351

Growth hormone (GH) p. 340, 364

for hypopituitarism p. 351

Hormone replacement therapy p. 680

for hypopituitarism p. 345

Hypopituitarism p. 345

Pituitary adenomas

hypopituitarism and p. 351

Radiation exposure

hypopituitarism p. 351


With hypopituitarism, “hypo” means under and “pituitarism” refers to the pituitary gland which normally secretes various endocrine hormones.

So hypopituitarism is the underproduction of hormones released by the pituitary gland, and the symptoms depend on which hormones are actually undersecreted.

If all of the pituitary hormones are affected, it’s called panhypopituitarism.

The pituitary is a pea-sized gland, hanging by a stalk from the base of the brain.

It sits just behind the eyes near the optic chiasm, which is where the optic nerves cross and the gland rests in a very small depression of the skull known as the sella turcica.

The pituitary gland produces and secretes hormones when it receives signals from another part of the brain called the hypothalamus.

Together, they form the hypothalamic-pituitary axis which regulates the release of all the major endocrine hormones.

The pituitary itself has two distinct parts: the anterior pituitary and the posterior pituitary.

The anterior pituitary, which is the front of the pituitary gland, contains a few different types of cells, each of which secretes a different hormone.

The largest group of cells are the somatotropes which secrete growth hormone, which goes on to promote tissue and organ growth.

The second largest cell group are the corticotrophs which secrete adrenocorticotropic hormone, or ACTH, which stimulates the adrenal glands to secrete cortisol, a hormone that controls the stress response, blood pressure, and metabolic regulation.


Hypopituitarism refers to the underproduction of any of the hormones released by the pituitary gland. If all of the pituitary hormones are underproduced, it's called panhypopituitarism. Hypopituitarism can be caused by tumors, pituitary hemorrhage or infarction, or accidental damage during radiation or surgery. Symptoms vary greatly depending on which hormones are impacted. Common symptoms include fatigue, weight gain, depression, low blood pressure, and problems with sexual function.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Harrison's Endocrinology, 4E" McGraw-Hill Education / Medical (2016)
  6. "Management of Hypopituitarism" Journal of Clinical Medicine (2019)
  7. "Hypopituitarism After Traumatic Brain Injury" Cureus (2019)

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