pathology of the pituitary gland Flashcards
anterior pituitary gland is also known as the
adrenohypophysis
the anterior pituitary secretes
trophic and non-trophic hormones
trophic hormones secreted by the anterior pituitary
TSH, FSH, LH, ACTH, MSH
non-trophic hormones secreted by the anterior pituitary
growth hormone and prolactin
anterior pituitary gland is derived from
rathkes pouch
posterior pituitary gland is also known as the
neurohypophysis
posterior pituitary gland is an
extension of neural tissue consisting go modified glial cells and axonal processes
hormones secreted by the posterior pituitary
oxytocin and anti-diuretic hormone (ADH) which are synthesised in the hypothalamus
how many types of cells does the anterior pituitary contain
3
what are the cells of the anterior pituitary
- ACIDOPHILS
- BASOPHILS
- CHROMATROPHS
acidophils contains
- somatotrophs which secrete GROWTH HORMONE
- mammotrophs which secrete PROLACTIN
basophils contain
- corticotrophs which secrete ACTH
- thyrotrophs which secrete TSH
- gonadotrophs which secrete FSH and LH
posterior pituitary is made up of
non-myelinated axons of neurosecretory neurons
pituitary hypofunction
rarely affects single hormones and most common causes panhypopituatarism
craniopharyngioma is derived from
remnants of rathkes pouch and are benign
craniopharyngioma accounts for
1-5% of intracranial tumours with the majority being suprasellar (above the pituitary gland)
incidence of craniopharyngiomas is
bimodal: highest incidence between age
- 5-15 and
- 60-70
craniopharyngiomas are
slow growing and are often cystic but they can calcify
presentation of craniopharyngiomas
- headaches
- visual disturbances
- growth retardation in childdren
management of craniopahryngiomas
surgical resection and radiotherapy
pathologies of the anterior pituitary gland
hyperfucntions: adenomas and carcinomas
hypofunction:
- trauma
- non-functioning pituitary adenomas
- infection
- infarctions: sheehans syndrome and pituitary apoplexy
- granulomatous infiltration
pathologies of the posterior pituitary gland
- diabetes insipidus
- syndrome of inappropriate ADH secretion SIADH
pituitary carcinomas
are very rare and are normally functionally secreting prolactin or ACTH
diabetes insidious can be
central or nephrogenic
central diabetes insipidus
insufficient production of anti-diuretic hormone
nephrogenic diabetets insipidus
renal resistance to the action of anti-diuretic hormone
adrenocortical adenoma
- well circumscribed small lesions
- yellow surface
- composed of cells resembling adrenocortical cells
- usually non-functional and are an incidental finding
adrenocortical carcinomas
- rare tumours
- likely to be functional
- virilising tumours are mostly malignant
spread of an adrenocortcial carcinoma
- local= retropertinoneum and the kidney
- metastasises usually vascular to the liver lung and bones
5 year survival of adrenocortical carcinoma
20%
whats it difficult to distinguish in adrenocortical tumours
whether they are benign or malignant
what is the only definite criterion for malignant of adrenococrtical tumours
metastasises
features suggesting it is a adrenocortical carcinoma rather than adenoma
- large size
- haemorrhage and necrosis
- capsular or vascular invasion
neuroblastoma
40% arise in the adrenal medulla while the rest along the sympathetic chain
neuroblastomas are composed of
primitive appearing cells
what is a poor prognostic indicator in neuroblastoma
amplification of N-myc and expression of telomerase
