pituitary disorders

Question 1

what is a functional pituitary tumour (rarer)

Answer 1

tumour which causes over production of one or more pituitary hormones.

Question 2

symptoms of functional tumour

Answer 2

effect of the over secreted hormone and may or may not show regulation of this over secreted hormone by negative feedback

Question 3

what is a non-functional pituitary tumour

Answer 3

don’t produce any hormones BUT can result in inadequate production of hormones sue to pressure on pituitary

Question 4

symptoms of non-functional tumour

Answer 4

headaches
visual problems
vomiting
nausea

Question 5

how to investigate and diagnose a pituitary tumour

Answer 5

1. find out its location and size using an MRI
2. asses the endocrine function to find out if its function or non-functional (tis can be done by measuring hormone levels in the blood/staining sections of biopsy for relevant hormone)
3. asses visual field defect

Question 6

what is hypopituitarism

Answer 6

less pituitary hormone problem

Question 7

causes of hypopituitarism

Answer 7

usually pituitary adenoma OR
radiation therapy
inflammatory disease
head injury

Question 8

what is panhypopituitarism

Answer 8

deficiency of all anterior pituitary hormones (ADH/oxytocin not usually affected unless tumour is affecting the hypothalamus too)

Question 9

what happens in GH deficiency (adults and children)

Answer 9

adults; decrease in exercise tolerance, decrease in muscle, increased body fat. (difficult to diagnose because secreted in pulses)
children; usually idiopathic, gene mutation or an inflammatory disease which has caused it.
little effect on fatal growth if parent has GH deficiency but if severe may have jaundice or hypoglycaemia
actual children have poor growth snd short stature

Question 10

effects of gonadotropin deficiency

Answer 10

lack of libido
infertility (women)
oligomenorrhoea (infrequent) or amenorrhea (absent)
impotence (men)

Question 11

effects of ADH deficiency and causes

Answer 11

causes; 
tumour in pit or hyp
radiotherapy or cranium 
pituitary surgery 
autoimmune 
meningtis 
effects; 
excess dilute urine = dehydration = polydypisa = diabetes insipidus

Question 12

what is diabetes insipidus

Answer 12

a disease in which the secretion of or response to the pituitary hormone vasopressin is impaired, resulting in the production of very large quantities of dilute urine, often with dehydration and insatiable thirst.

Question 13

what is hyperpituitarsm

Answer 13

caused by hyper secreting ademoa of prolactin GH and ACTH

Question 14

prolactin excess symptoms

Answer 14

galactorrhea 
gynecomastia (hard breast tissue)
hypogonadism (diminished testes/ovary activity)
amenorrhea 
erectile dysfunction

Question 15

how is prolactin regulated

Answer 15

regulated by prolactin and dopamine from hypothalamus as in dopamine inhibits secretion and prolactin stimulates secretion

Question 16

causes of prolactin excess

Answer 16

prolacitoma (adenoma secreting prolactin) 
pregnancy 
suckling 
stress and exercise 
drugs e.g antidepressants

Question 17

treatment for prolactin excess

Answer 17

dopamine receptor agonists to inhibit secretion of prolactin from pituitary e.g Cabergoline
some people also undergo tram-sphenoidal surgery (pituitary accessed through nose)

Question 18

symptoms of GH excess (GH secreting pituitary)

Answer 18

headache, visual field defects
broad nose, coarse facial features, thick lips
enlargement of hands and feet
greasy skin and excess sweating
depend voice because hypertrophy of soft tissue
if in childhood then have gigantism
also antagonises actions of insulin = diabetes

Question 19

treatment of GH secreting pituitary adenoma

Answer 19

1. surgery to remove adenoma/radiation/drug therapy
2. dopamine agonists - somastatin has v short half life so has limited use BUT have synthesised new ones with longer half lives
3. antagonists of GH receptor e.g pegvisomant
   (in order of what is first line)