Definition
Pituitary disorders are characterized either by a failure of secretion of pituitary hormones or by tumours, which cause local pressure effects or specific syndromes due to hormone overproduction.
Key Points
- Acromegaly is often insidious in onset and slow to be diagnosed.
- Deficiencies of pituitary function are generally tested for by stimulation tests and overactivity by suppressions tests. Direct serum hormone levels may also be measured.
- Imaging the pituitary gland is best done by MRI.
Common Causes
- Primary failure of anterior pituitary secretion (GH, gonadotrophins, TSH and ACTH) causes pan-hypopituitarism (Simmonds’ disease):
pressure from a tumour – adenoma or craniopharyngioma
infarction or ischaemia – haemorrhagic shock, especially postpartum (Sheehan’s syndrome)
inflammatory – meningitis, pituitary abscess, sarcoidosis
infiltrative – haemochromatosis
iatrogenic – surgery, radiotherapy.
- Secondary anterior pituitary secretion failure from hypothalamic causes.
- Failure of ADH production from the posterior pituitary gland leads to central diabetes insipidus (CDI). Nephrogenic diabetes insipidus (NDI) results from renal resistance to ADH. Causes of CDI are:
idiopathic – some genetic (abnormality of ADH gene on chromosome 20)
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
