Pituitary Tumours Flashcards
How common are pituitary tumours?
Relatively common
What percentage of CNS tumours are pituitary tumours?
10-15%
Where do most pituitary tumours arise?
Anterior lobe
Histologically what are all primary tumours?
Benign adenoma
Why can Pituitary tumours be dangerous?
Dangerous due to their location e.g.
they can compress the optic chiasma and cause visual disturbances or blindness
May extend into cavernous sinus
local pressure symptoms
Clinical syndromes associated with abnormal hormone production
What is the Cavernous sinus?
A large channel of venous blood creating a “sinus” cavity bordered by the sphenoid bone and the temporal bone of the skull. The cavernous sinus is an important structure because of its location and its contents which include the third cranial (oculomotor) nerve, the fourth cranial (trochlear) nerve, parts 1 (the ophthalmic nerve) and 2 (the maxillary nerve) of the fifth cranial (trigeminal) nerve, and the sixth cranial (abducens) nerve.
PRL secreting adenoma - hypogonadism+Galactorrhoea
Classified by WHO (2017) what are pituitary tumour cell types?
Corticotrophs
Somatotrophs
Lactotrophs
Thyrotrophs
Gonadotrophs
What were Pituitary tumours classed as in the past?
Acidophilic, eosinophilic, basophilic
What is the most common Pituitary Adenoma?
Lactotrophs are the commonest
Lactotrophs
Secrete prolactin and some may also secrete growth hormone (GH)
Gonadotrophs
30% are non-secreting macroadenomas, these most recently are referred to as “whispering” gonadotrophs) some – secrete luteinising hormone (LH), follicle stimulating hormone (FSH) and thyroid stimulating hormone(TSH)
Corticotrophs
10-15% of cases – secrete adrenocorticotrophic hormone (ACTH)
Somatotrophs
Secrete growth hormone (GH)
Thyroid lesions
Extremely rare (secrete TSH)
Posterior Pituitary
Tumours are occasionally seen called pituicytomas
Generally arise from glial cells
Pituitary Adenoma Tumour Effects
Headache
Visual impairment (blindness, bitemporal hemianopia, tunnel vision
homonymous hemianopia)
Thirst and increased appetite
Loss of recent memory
Partial or complete hypopituitarism
Partial or complete hyperpituitarism
What is Hypopituitarism?
Rare condition
Pituitary secretes inadequate amounts of one or more of its hormones
Can be progressive, eventually under secreting all pituitary hormones
What does Hypopituitarism cause in children?
Failure to grow
Failure of pubertal development
What does Hypopituitarism cause in adults?
Malaise, pale “waxen doll” complexion, intolerance to cold, amenorrhoea, loss of libido, impotence, loss of secondary sexual hair distribution, acute abdominal pain (hypopituitary crisis) and low blood sugar
Who are Craniopharyngioma tumours most common in?
Most often diagnosed in children, teenagers and young adults.
Where do Craniopharyngioma tumours occur?
Tend to grow near the base of the brain, just above the pituitary gland. Craniopharyngiomas do not usually spread, but they occur close to important structures in the brain and can cause problems as they grow. They can cause changes in hormone levels and problems with eyesight. Children with craniopharyngioma can have weight gain and growth problems.
ACROMEGALY hyperactivity – excessive growth hormone production.
Adults over 20-25
Occasionally runs in families
Acromegaly signs and symptoms
Enlarged hands and feet
Coarsened, enlarged facial features
Coarse, oily, thickened skin
Excessive sweating and body odour
Small outgrowths of skin tissue (skin tags)
Fatigue and muscle weakness
A deepened, husky voice due to enlarged vocal cords and sinuses
Severe snoring due to obstruction of the upper airway
Impaired vision
Headaches
Enlarged tongue
Pain and limited joint mobility
Menstrual cycle irregularities in women
Erectile dysfunction in men
Enlarged liver, heart, kidneys, spleen and other organs
Increased chest size (barrel chest)
What is Macroadenoma?
Excess growth hormone
What is Gigantism?
In children whose pituitary produces excess growth hormone the condition is known as gigantism
Cushing’s Syndrome Corticotrphic adenoma secreting excessive ACTH
Weight gain
Sleep disorders
Raised blood pressure
(easy) bruising
Moon face
Thin, vulnerable skin
Psychological changes
Blurred vision
Osteoporosis
Irregular or absent menstrual cycles
Excessive hair growth
Muscular weakness
Impaired wound healing
Fatigue
Pituitary Diagnosis and Investigations
History
CT
MRI
Lateral skull x-ray
Assay of anterior pituitary hormones
Pituitary Adenoma Aims of Treatment
Reverse neurological impairment
Stem tumour recurrence
Replace hormones
Normalize levels of elevated hormones
Pituitary Adenoma Management
Tumours < 1 cm in diameter (microadenomas; contained within Pituitary fossa) - suitable for trans-sphenoidal resection
Large prolactinomas (macroadenomas) - craniotomy – Transfrontal surgery alone is not adequate due to the high rate of recurrence Postoperative radiotherapy is recommended
Dopamine agonists – Bromocriptine/Cabergoline
Sythetic somatostatin analogues – Octeroide/Somatostatin
Pituitary Adenoma post-operative radiotherapy
External beam RT
Stereotactic radiotherapy
Yttrium 90 or Gold 198 implantation
Proton beam therapy
Daily recommended tumour tumour dose 1.8 Gy delivered over 5 weeks
There is some evidence that in order to avoid recurrence this dose must be exceeded
45 Gy / 25 # / 5 weeks
Pituitary Adenoma Early Sequelae
Erythema
Epilation
Headache
6 years post radiotherapy pituitary function may be poor
Hormone replacement therapy (HRT) is required eg corticosteroids, thyroxin and testosterone
Pituitary Adenoma HRT
All patients will require treatment which will have to be individually designed
Diabetes insipidus DDAVP injection/nasal spray /oral
Men – testosterone replacement therapy
Women – cyclical oestrogen and progesterone (the pill)
FSH and LH to sustain fertility
Children need aggressive GH therapy (adults don’t require GH)
Thyroxin
The HRT must imitate normal hormone levels
