Brain tumours 3 Flashcards
What is the most common type of pituitary tumours and are pituitary tumours a common type of intracranial tumours ?
- The most common type of pituitary tumours are pituitary adenomas (they are benign but cause compression etc and hormone problems)
- They account for 10% of intracranial tumours
Go over the hormones produced by the pituitary gland
What is the range of symptoms which can be caused by pituitary tumours ?
Symptoms can be caused by a tumour producing extra hormones, or by not producing enough hormones. Other symptoms can be caused by the tumour pressing on other structures e.g. CN’s 3,4,6
These include headaches and vision problems (bitemporal heminopia due to compression on the optic chiasm)
What is the investigations which should be carried out in someone with a pituitary tumour ?
MRI to define supra and infra-sellar extension
Then measure hormone levels:
- Prolactin
- GH & IGF-1
- ACTH
- Cortisol
- TSH, FT4, FT3
- FSH and LH
Check their visual acuity and Visual Fields
What are some of the clinical signs of raised prolcatin in females ?
- Galactorrhoea - milky discharge from nipples
- Menstrual irregularity
- Ammenorrhoea
- Infertility
What are some of the clinical features of raised prolactin in males?
- Erectile dysfunction
- Decreased body and facial hair
- Uncommonly, enlarged breasts (gynecomastia)
- Visual field abnormal
- Headache
What is the treatment of raised prolactin levels ?
Cabergoline cures; rarely need surgery
What are the characteristic features of acromegaly ?
- Gaint (tall)
- Thickened skin
- Large jaw and hands
- Sweaty
- Snoring/sleep aponea
- DM
How is acromegaly diagnosed?
- Measure serum insulin-like growth factor 1 (IGF-1)
- Random serum growth hormone (GH)
- Oral glucose tolerance test (OGTT) - measure GH during it as when given glucose GH levels should decrease but in acromegaly they remain unchanged
What is the treatment of acromegaly ?
1st line = pituitary surgery (transsphenoidal)
Then retest using OGTT
2nd line = somatostatin analogue (octreotide or lanreiotide) + dopamine agonist (carbergoline)
What is cushings due to ?
- Excess cortisol
- Excess mineralocorticoid
- Excess androgen
Describe the clinical presentation of cushings syndrome
- Thinning of skin - stretch marks
- Increased Abdominal fat, buffalo hump
- Muscle wasting causing thin arms and legs
- Poor wound healing/ easy bruising
- AVN
- Moon face
- Cataracts
How is cushings diagnosed ?
- Screening test = overnight dexamethasone suppression test
- Diagnosis made on low dose dexamtheosone suppression test (48hrs)
What are the different causes of cushings syndrome ?
- Pituitary (majority)
- Adenoma of adrenal gland
- Ectopic - e.g. from lungs, pancreas etc
- Alcohol and depression
- Steroid medication
(note ACTH is what indirectly stimulates cortisol so if its not something in the adrenal gland then it needs to be producing ACTH to stimulate its production)
How does ACTH levels vary with the different causes of cushings ?
- Pituitary < 300
- Adrenal < 1
- Ectopic > 300
What are the 2 main types of diabetes insipidus ?
Central and nephrogenic
- Central = problem with the production/secretion of ADH
- Nephrogenic = no problem with production/secretion but cells not responsive to ADH
What are the causes of central diabetes insipidus ?
Familial:
- isolated in most cases
- DIDMOAD (DI, DM, optic atrophy, deaf)
Acquired:
- Idiopathic in 50%
- Trauma; road accidents, surgery, skull fracture
RARE:
- Tumour, sarcoid, ext irradiation, meningitis
How is diabetes insipidus diagnosed ?
Water deprivation test
What is the treatment of diabets insipidus
- Desmospray or
- Desmopressin injections or tablets
Essentially giving ADH
What are the causes of anterior hypopituitarism ?
- Pituitary tumours/ metastatic lesions
- Local brain tumours
- Granulomatous disease - e.g. TB, sarcoidosis
- Trauma
What are the signs/symptoms of anterior hypopituitarism ?
Depends on the hormones which are lacking in secretion:
- Growth Hormone; growth failure
- TSH; hypothyroidism
- LH/FSH; Hypogonadism
- ACTH; hypoadrenal
- Prolactin; none known
The general signs/symptoms of anterior hypopituitarism
- Menstrual irregularities (F)
- Infertility, impotence
- Gynaecomastia (M)
- Abdominal obesity
- Loss of facial hair (M)
- Loss of axillary and pubic hair (M&F)
- Dry skin and hair
- Hypothyroid faces
- Growth retardation (children)
