Anterior Pituitary Disorders

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.

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

• 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

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

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

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

• Pituitary macroadenoma that hemorrhages
• Adverse effect from surgery to remove adenoma