Anterior Pituitary Disorders

Name 7 disorders of the anterior pituitary?

Remember anterior pituitary produces FLAT PiG (FSH, LH, ACTH, TSH, Prolactin, GH) so in that order…

  1. FSH or LSH producing tumors – called functional gonadotroph adenomas (FGA)
  2. ACTH producing adenoma – Cushing’s disease
  3. TSH producing adenoma – Central hyperthyroidism
  4. Prolactin producing adenoma (prolactinoma)
  5. GH producing adenoma (gigantism in kids, acromegaly in adults)
  6. Hypopituitarism – can be due to infection, infarction, or surgery. Acute hypopituitarism can lead to coma and death.
  7. Empty Sella syndrome – pituitary is located elsewhere rather than in the sell turcica, so not seen there on MRI.
What are 4 expected symptoms & signs for hyperprolactinemia?
  1. Hypogonadism – in women this results in irregular menses or amenorrhea and infertility. In both it results in decreased libido.
  2. Galactorrhea – more commonly seen in women but in rare cases men can present with this too. Due to prolactin’s effect in inducing lactation
  3. Headaches from macroadenomas due to mass effect
  4. Bitemporal hemianopia from macroadenomas due to compression of optic chiasm
Name 4 causes of hyperprolactinemia
  • Pregnancy – normal part of pregnancy is elevated prolactin
  • Prolactinoma – a prolactin secreting pituitary adenoma
  • Medications that elevate prolactin e.g. dopamine antagonists like haloperidol, domeperidone
  • Hypothyroidism – high TRH stimulates prolactin production
What is the workup for suspected prolactinemia?
  1. First step: check medications
  2. Second step: rule out pregnancy (females, with beta-hCG), rule out hypothyroidism (get TSH), and get serum prolactin level
  3. Final test: brain MRI to see the mass
What is the treatment for a prolactinoma?
  1. First step is medication – dopamine agonists. Cabergoline is better tolerated but expensive, bromocriptone is the less expensive option. Both will help shrink the tumor and resolve symptoms. Start at lower dose then checking progression of serum prolactin increase until levels normalized.
  2. Surgery (trans-sphenoidal pituitary resection) – is done if medications fail or if there are significant neurological impairments
  3. Radiation is done as a last resort – if medications and surgery fail
Is there a difference between how men and women with a prolactinoma present? Yes. Women will feel the effects of elevated prolactin sooner because the resulting hypogonadism causes menstrual irregularity or amenorrhea in women, also prolactin will cause galactorrhea more often in women (rare in men). By the time men present with symptoms, the adenoma is larger – a macroadenoma – and mass effect will lead to headaches and bitemporal hemianopia (loss of vision to the sides of the head (temples)).
What is the management of prolactinemia due to hypothyroidism? Thyroxine
What is the management of prolactinemia due to the antipsychotic haloperidol? If possible switch to an antipsychotic with less of an effect on prolactin e.g. quetiapine or aripiprazole.
What causes bitemporal hemianopia? Compression of the optic chiasm by a large adenoma (macroadenoma)
High levels of growth hormone in a child can cause what disease? Gigantism – the growth plates haven’t closed yet, so long bones grow leading to large stature.
High levels of growth hormone in an adult can cause what disease? Acromegaly – growth plates have closed so they won’t get taller, but the hands and feet will get larger and facial features will become “coarse”. Visceral organs will also become larger, most concerning is the heart – enlarged heart muscle leads to diastolic (can’t fill) heart failure and death. GH stimulates gluconeogensis in the liver normally, so excess GH means high blood sugars and eventually diabetes mellitus.
What is the workup of acromegaly?
  1. First – You want to check the growth hormone level but it is pulsatile (varies greatly) so instead we check ILGF-1 (insulin-like growth factor 1) which is produced by the liver in response to GH.
  2. Second – we order a glucose tolerance test – here called a glucose suppression test – to see if glucose will suppress (negative feedback on) GH. Failure of glucose to suppress GH suggests that this is a tumor producing GH so …
  3. Final – get MRI to look for mass
What is Empty Sella Syndrome No pituitary is found on MRI. This is an incidental finding – MRI done for another reason, no symptoms in patient of pituitary related problems.
What is the management of empty sella syndrome? None – doesn’t require treatment.
List 6 symptoms and/or signs of hypopituitarism
List 4 causes of pituitary apoplexy
  • Pituitary macroadenoma that hemorrhages
  • Adverse effect from surgery to remove adenoma

Review Questions

https://www.hopkinsmedicinereview.com/documents/Section06.pdf – endocrinology

https://acpinternist.org/weekly/archives/2020/07/07/3.htm – decreased libido, fatigue

https://acpinternist.org/weekly/archives/2020/04/14/3.htm – unable to achieve pregnancy

https://acpinternist.org/weekly/archives/2020/01/14/3.htm – 45 year old man with anorexia, dizziness, weakness after having pituitary adenoma surgically removed.

https://acpinternist.org/weekly/archives/2019/08/06/3.htm – pregnant woman in MVA with low sodium

https://acpinternist.org/weekly/archives/2019/09/24/3.htm – flushing face 1 year

https://acpinternist.org/weekly/archives/2017/09/12/3.htm – amenorrhea for 4 months

https://acpinternist.org/weekly/archives/2017/05/09/3.htm – man with 2 years of low libido

https://acpinternist.org/weekly/archives/2017/12/12/3.htm – incidental adrenal mass

https://acpinternist.org/weekly/archives/2017/06/13/3.htm * – episodic palpitations

https://acpinternist.org/weekly/archives/2017/03/07/3.htm* – sudden onset erectile dysfunction

https://acpinternist.org/weekly/archives/2016/11/01/3.htm – man with fatigue & low libido for 2 years

https://acpinternist.org/weekly/archives/2016/08/02/3.htm – incidental pituitary adenoma

https://acpinternist.org/weekly/archives/2014/08/19/3.htm* – man with wrist fracture, anemia

https://acpinternist.org/weekly/archives/2014/01/28/3.htm – amenorrhea, galactorrhea in 33 year old woman

https://acpinternist.org/archives/2014/02/mksap.htm – man with fatigue, muscle weakness

https://acpinternist.org/weekly/archives/2014/09/30/3.htm – urinary frequency, increased thirst, taking lithium

https://acpinternist.org/weekly/archives/2013/10/22/3.htm – woman with increasing fatigue and weight gain, had surgery to remove pituitary adenoma 4 years ago

https://acpinternist.org/weekly/archives/2011/03/08/3.htm – woman with fatigue, nausea, poor appetite

https://acpinternist.org/weekly/archives/2011/10/25/3.htm – woman with 2 year history of infertility

https://acpinternist.org/weekly/archives/2011/04/19/3.htm* – woman with irregular menses and infertility

https://acpinternist.org/weekly/archives/2010/01/26/3.htm – woman with fatigue, weight gain, constipation. Had resection of craniopharyngioma.

https://www.acpjournals.org/doi/10.7326/AWED202108170 *scroll down to question – incidental adrenal adenoma

https://www.acpjournals.org/doi/10.7326/AWED201907160 – case 1: woman with adrenal mass; case 2: man with adrenal mass

https://diabetes.acponline.org/archives/2013/03/08/4.htm – muscle weakness and uncontrolled diabetes







kaplan – pituitary apoplexy