Pituitary tumours and other Sellar disorders Flashcards
How are pituitary adenomas classified
According to their size:
macroadenomas 1+ cm
Microadenomas
What are functioning pituitary tumours associated with
excess anterior pituitary hormone secretion
When is the peak age to develop a pituitary tumour
around 30-60 years
Males usually present earlier than females. true or false
false - women usually present before males
What are the most common pituitary macro adenomas
Non-functioning pituitary adenomas
What is responsible for tumours that occur in MEN1
Loss of function mutations of MEN 1
What are some of the presenting complaints of patients with a pituitary tumour
Hyper secretion of pituitary hormone
hypopituitarism
headache
compression of the surrounding structures such as the optic chiasm
How might a prolactin-secreting adenoma present
galactorrhoea
amenorrhoea
infertility
impotence
What do ACTH secreting adenomas cause
Cushing’s disease
What do GH secreting adenomas cause
acromegaly
How do TSH secreting adenomas present
secondary hyperthyroidism with or without a goitre
What might a pituitary tumour in the anterior pituitary result in
A decreased secretion of anterior pituitary hormones due to compression or destruction of the surrounding normal pituitary cells
How might a GH deficiency present
Fatigue impaired psychological well-being reduced energy muscle strength and exercise capacity increased abdominal adiposity
How might an LH and FSH deficiency present in males
Reduced libido impotence infertility loss of body hir fine premolar wrinkles flushes
How might an LH and FSH deficiency present in females
Oligomenorrhoea amenorrhoea infertility dyspareunia breast atrophy flushes
How might a TSH deficiency present
Fatigue apathy muscle weakness cold intolerance constipation weight gain dry skin
How might an ACTH deficiency present
fatigue weakness nausea vomiting weight loss hypoglycaemia loss of pubic and axillary hair in females
How might a vasopressin (ADH) deficiency present
Polyuria
nocturia
polydipsia
What causes headaches
stretching or invasion of the dura
Large tumours with suprasellar extension may occasionally cause obstructive hydrocephalus
What might involve the optic chiasma (bitemporal visual field loss)
suprasellar extension of the tumour
What can cause hyperprolactinaemia which may cause hypogonadism
stalk compression
What may cause cranial nerve palsies and diplopia
Lateral extension and cavernous sinus invasion
What might inferior extension result in
CSF rhinorrhoea due to erosion of the sphenoid sinus
What are pituitary incidentalomas
Mass lesions (usually adenomas) that are deleted following radiological imaging of the skull or brain for another clinical reason
What are some investigations for suspected pituitary tumours
Basal and dynamic pituitary function tests
pituitary MRI
formal visual field assessment
What are 2 lab pitfalls we need to be aware of when measuring prolactin levels
Hook effect - assay uses antibodies that recognise two different sites on the prolactin molecule
Very high prolactin levels may be artifactual reported as normal or only modestly elevated
Hyperprolactinaemia may be due to decreased clearance of a complex of prolactin with IgG - macroprolactin
In what cases is IGF-1 levels high
In patients with GH secreting pituitary tumours causing acromegaly
Whate are some investigations for ADH deficiency
Measurement of serum and urine osmolality and sodium concentration and the water deprivation test
When is the insulin tolerance test contraindicated
What should be done instead
Patients with a history of epilepsy or ischaemic heart disease
Glucagon test
What is the preferred imaging modality for the pituitary gland
MRI
What are the treatment options for patients with pituitary tumours
Surgery - reduce local compression effects, reduce excess hormone secretion
What is the first line surgery for almost every case
Trans-sphenoidal
How should secondary adrenal insufficiency be treated
Hydrocortisone but only after excluding or treating adrenal insufficiency
Why does fluid balance have to be very carefully monitored post operatively
to watch for the possible development of diabetes insipius
How does diabetes insipidus present
poluria
What in the patients urine can be tested as a quick test for diabetes insipidus
Specific Gravity
How is diabetes insipidus diagnosed
If the plasma osmolality is high or plasma sodium is over 145mmolL in the presence of an inappropriately low urine osmolality/ SG
What drug can be given if sodium is too high and they are not managing to drink enough
desmopressin
What must be checked 7-10 days post op and why
Serum sodium as there is a risk of hyponatraemia
How is cerebral salt wasting treeated
saline administration
how is the syndrome of inappropriate ADH (SIADH) treated
fluid restriction
What are the indications of radiotherapy following a pituitary surgery
shrink residual or recurrent tumour
reduce the likelihood of regrowth treat persistent hormone hyper secretion
What are some short term complications of radiotherapy on the pituitary
hair loss
headache
nausea
What are some long term complications of radiotherapy on the pituitary
Hypopituitarism
Visual impairment
What is included in the follow up from pituitary surgery
Visual acuity and fields
Pituitary function testing including serum cortisol 0am
When should a pituitary MRI be repeated
4 months after the surgery - so that the immediate inflammatory post op changes do not influence the results
What is pituitary apoplexy
Acute hemorrhagic infarction of a pituitary tumour resulting in gland destruction and compression of surrounding structures by the oedematous enlarged pituitary tumour
How does pituitary apoplexy present
acute headache meningism visual impairment ophthalmoplegia sometimes altered consciousness
What are some investigations for pituitary apoplexy
PItuitary MRI and pituitary function tests
What is the treatment for pituitary apoplexy
Life saving IV Hydrocortisone replacement
Surgery within 8 days although not for those with no significant problems
What is Sheehan’s syndrome
Pituitary gland necrosis caused by hypertension due to postpartum haemorrhage
How might patients with Sheehan’s syndrome present
After delivery
failure of lactation
failure to resume menses
fatigue, weight loss, anorexia
What is empty sella syndrome characterised by
an enlarged sella filled with CSF
What might primary empty sella syndrome be due to
a defective and enlarged diaphragma sella opening
What might cause empty sella syndrome
A developmental anomaly
increased intracranial pressure
compression and posterior displacement of the anterior pituitary
Who is empty sella syndrome more common in
middle aged women
What might secondary empty sella syndrome be due to
infarction
surgery
radiotherapy of a pituitary adenoma
What are craniopharyngiomas
benign tumours that arise from squamous epithelial remnants of Rathke\s pouch
What do craniopharyngiomas commonly cause
diabetes insipidus
What are the major presenting symptoms of craniopharyngiomas
Growth retardation in children and visual abnormalities in adults
What are meningiomas
Usually benign tumours arising from the meninges
What are germ cell tumours usually associated with
simultaneous lesions in the pineal gland
What might abscess in the pituitary result form
local spread - e.g. from sphenoid sinusitis
or may be secondary to septicaemia
What is lymphocytic hypophysitis characterised by
lmphocytic infiltration of the anterior pituitary followed by fibrosis
Who does lymphocytic hypophysitis affect
women most commonly during pregnancy or the postpartum period
What is sarcoidosis
An inflammatory granulomatous multisystem disorder that may affec multiple organs such as the eyes, skin, lungs, joints and CNS
What is hereditary haemochromatosis
An inherited disorder characterised by increased intestinal iron absorption and iron deposition in various grans due to mutations in the HFE gene
Traumatic brain injury may result in what
hypopituitarism
What are the 3 main complications of pituitary surgery
Cerebral infection
diabetes insipidus
hypopituitarism
