Syndromes of anterior pituitary hyperfunction

Question 1

Growth hormone hyperfunction

Answer 1

After puberty: Acromegaly

• Can be due to a GH secreting pituitary adenoma
• Difficult to diagnose and test due to the pulsating nature of GH secretion. We can use OGTT where the GH would normally decrease or we can measure IGF-1 which will be increased
• Will lead to abnormal growth, increased size of hands and feet, growth of non-long bones, enlarged organs, DMT2, HTN, mass effect
• Treatment with surgery and somatostatin analogues

Before puberty: Gigantism

Question 2

Prolactin hormone hyperfunction

Answer 2

Comprises 40% of all pituitary adenomas, it is benign. It is also unresponsive to dopamine (which usually inhibits prolactin release). Causes a decrease in reproductive functions and estrogen/testosterone secretion.
In females: amenorrhea, anovulation, galactorrhea
In males: impotence and spermatogenesis dysfunction
Diagnosis through a metoclopramide (dopamine antagonist) test: stimulates Prolactin. Can also test with MRI and visual field tests (occasionally the prolactinomas are quite large). Therapy with dopamine.

Question 3

ACTH hyperfunction

Answer 3

Cushings syndrome

Question 4

TRH hyperfunction

Answer 4

Hyperthyroidsm

Question 5

FSH/LH hyperfunction

Answer 5

no clinically observable function