Pituitary Disorders Flashcards
What are the two types of pituitary tumours and why can they be harmful
Non-functioning tumours - can cause inadequate production of one or more of the hormones due to pressure from tumour on glandular tissue, tumour can press on surroundings causing other problems
Functioning tumours - cause overproduction of one or more pituitary hormone
What is hypopituitarism and what are its causes
Insufficient pituitary hormone production
Causes - pituitary adenoma, radiation therapy, inflammatory disease, head injury
Usually secondary to mass effect from adenoma
What is a complete deficiency of all anterior pituitary hormones called
Panhypopituitarism
What are the effects of growth hormone deficiency
Adults - decreased exercise tolerance, increased body fat, decreased muscle strength, reduced sense of well-being
Fetus - little effect on fetal growth, severe prenatal deficiency can result in hypoglcaemia and jaundice
Children - poor growth and short stature
Effects of hypogonadism
Women - lack of libido, infertility, oligomenorrhea or amenorrhea
Men - decreased libido, impotence
Effects of ADH deficiency
Dehydration odue to excess excretion of dilute urine
Polydipsia
What effects does a non-functioning pituitary tumour pressing on the surrounding structures have
Headaches
Visual problems - compression of optic nerve
Vomiting
Nausea
How are pituitary tumours investigated
Delineation of anatomy, size and topographical location of pituitary or parapituitary mass usually by MRI
Assessment of visual field defects
Assessment of endocrine function - determine whether hormone excess or deficiency
How does hypopituitarism usually progress
Typically have progressive loss of anterior pituitary function with GH and LH/FSH usually first hormones affected
What are the causes of GH deficiency
In adults usually due to the mass effects from pituitary adenoma
In children GH deficiency is typically idiopathic but specific gene mutations and autoimmune inflammation has caused some cases
What causes gonadotropin deficiency
Mass effects from pituitary adenoma
Name some types of hypopituitarism
GH deficiency
Gonadotropin deficiency
ADH deficiency
TSH and ACTH deficiency
What can cause TSH and ACTH deficiency
Pituitary adenoma
What type of disease does ADH deficiency represent
Cranial form of diabetes insipidus
What causes ADH deficiency
Hypothalamic tumour
Pituitary tumour extended up intohypothalamus
Cranial radiotherapy
Pituitary surgery
Autoimmune infiltration
Infection - meningitis
What are the three main conditions caused by excess pituitary hormone production and what are they caused by
Prolaction excess
Growth hormone excess
ACTH excess
Caused by hypersecreting pituitary adenoma
What symptoms does hyperprolactinaemia cause
Galactorrhoea
Gynecomastia
Hypogonadism
Amenorrhea
Erectile dysfunction
What can hyperprolactinaemia cause due to negative feedback
Prolactin inhibits GnRH secretion and therefore FSH and LH secretion causing hypogonadism
What is a common cause of hyperprolactinaemia
Prolactinoma - pituitary adenoma secreting prolactin
What are the other causes of hyperprolactinaemia
Pregnancy
Suckling
Stress
Exercise
Drugs like antipsychotics and antidepressents
What treatments are there for hyperprolactinaemia
Dopamine receptor agonists - cabergoline
Rare cases - Trans-sphenoidal surgery or Radiotherapy
What are the effects of growth hormone excess caused by a GH secreting pituitary adenoma
Local mass effects due to large pituitary adenoma - headache, visual field defects, other cranial nerve palsies
Changes in physical appearance - broad nose, coarse facial features, thick lips, prominent supraorbital ridge
Enlargment of hands and feet
Skin often greasy with excessive sweating
Deepening of the voice
Gigantism in children if left untreated
Metabolic complications including diabetes mellitus
What are the treatment options for patients with growth hormone excess
Surgery to remove adenoma
Radiation therapy
Drug therapy - dopamine receptor agonists
