pituitary 2 Flashcards
adrenocorticotrophic hormone hyperfunction
Cushing disease
adrenocorticotrophic hormone (ACTH) hypofunction
hypoadrenalism
follicle stimulating hormone (FSH) luteinising hormone (LH) hyperfunction
usually silent, sometimes menstrual abnormalities, testicular enlargement, fertility issues
FSH or LH hypo function
hypogonadism
growth hormone hyper function
acromegaly
growth hormone hypoofunction
decreased muscle mass, fatigue, some forms of dwarfism
TSH hyperfunction
hyperthyroidism - but more often due to thyroid disease
TSH hypofunction
hypothyroidism
PRL hyperfunction
hyperprolactinaemia
PRL hypofunction
isolated deficiency rare, causes lactation failure if breastfeeding
plurihormonal hypofunction
panhypopituitarism
vasopressin hyperfunction
SAIDH
vasopressin hypofunction
diabetes insipidus
oxytocin excess or deficiency
not associated with clinical disease
hyperpituitarism
- excess secretion of pituitary hormones - anterior and posterior have different causes and effects
causes of pituitary hyper function
- pituitary adenoma
- secondary hyperplasia (increased stimulation of the hypothalamus
- pituitary carcinoma (rare)
pituitary adenoma
- slow growing tumours, benign, epithelial with neuroendocrine phenotype
- clinical proliferation of one type of pituitary cell
- arise in the anterior pituitary
mass effect in pituitary adenomas
- raised intracranial pressure
- bony erosion
- local pressure on third ventricle, hypothalamus, optic chiasma (giving bi temporal hemianopia) or cranial nerves 3, 4, 5, 6
altered hormonal secretion
- anterior, posterior or both
- hyperpituitarism - hormones produced by neoplastic cells
- hypopituitarism - normal pituitary compressed by tumour, becomes atrophic or ischaemic
most common cause of hyperpituitarism
pituitary adenoma
micro adenoma
<1cm
macro adenoma
> 1cm
pathological phenotypes of pituitary adenomas
- immunohistochemical phenotype
- H&E cell type (acidophil, basophil, chromophore adenoma)
- ultrastructural phenotype based on size and morphology of granules
functional (secretory) adenomas
- lactotroph/prolactinoma - amenorrhea, galatorrhoea, infertility, loss of libido
- somatotroph - gigantism, acromegaly
- corticotroph - Cushing’s disease
- plurihormonal -
- gonadotroph - secrete hormones inefficiently and variably, difficult to recognise, grow and have mass effects and paradoxical hypopituitarism
- thyrotroph
non functional adenomas
null-cell adenomas
- these usually still express hormonal markers by immunohistochemistry
other causes of hyperprolactinaemia
can occur due to physiological hyperplasia - pregnancy, lactation
head trauma or mass effect
acromegaly/gigantism
- excess growth hormone
- enlargement of hands, thickening of the skin, skull bones, macroglossia, wide spaced teeth, hyperpigmentation, seborrhoea
- severe headache, arthritis, cardiomegaly, hepatic fibrosis, insulin resistance (T2D), renal failure
acromegaly is when
- happens after growth plates are fused
gigantism is when
happens before the growth plates are fused
atypical adenoma and carcinoma
anterior pituitary
- rare, usually non-function
- invasive, high mitotic rate, pleomorphism
craniopharyngioma
- mostly in childhood, early adulthood
- derived from rathke’s pouch remnants
- often large, 3-4cm, cystic, calcified
- history recapitulates enamel organ of tooth embedded in fibrous stroma
- usually benign but often locally invasive, difficult to treat
secondary neoplasms in the pituitary
more common in the posterior pituitary, may present as diabetes insidious (breast and lung are commonest primary sites)
