Neuroendocrine tumours Flashcards
Define a neuroendocrine tumour
Neuroendocrine tumour = neoplasm that arises from cells of the endocrine and nervous systems. Most commonly occur in intestine and here they are known as carcinoid tumours
What are the three main points to consider when assessing a tumour?
- ) Pressure on local structures
- ) Pressure on the normal pituitary: underproduction
- ) Functioning pituitary tumour: over production
What symptoms can tumours pressing on local structures e.g. optic nerve cause?
- Headaches: tumour can stretch the dura
- Hydrocephalus
- Visual field defects: get bitemporal hemianopia
- Cranial nerve palsies: pressure in the cavernous sinus of III/IV/VI lesions
- Pressure on the hypothalamic centres: obesity/thirst/precocious puberty in children
- Cerebrospinal fluid rhinorrhoea (downward extension through the pituitary fossa): CSF drips out of nose
What symptoms will you experience when a tumour is causing pressure on the normal pituitary and is causing an underproduction of hormone?
- This can lead to hypopituitarism
- Adults experience: pallor/loss of body hair/central obesity/soft skin
- Children: won’t grow
- Has a slow onset
- (need to do different tests to test each different axis, check lecture notes)
What happens when you have a functioning pituitary tumour?
- If tumour is derived from cell type that normally creates a hormone, it will most likely produce that hormone
- This happens in 3 ways:
1. ) Prolactinoma: e.g. prolactinoma microadenoma
2. ) Acromegaly + gigantism
3. ) Cushing’s disease - Or v rarely: TSH/LH/FSH secreting
Define hyperprolactinaemia
- When too much prolactin is produced.
Describe the epidemiology of prolactinoma
- Common in young women
Describe the pathology/aetiology of prolactinoma
- Prolactin release is under tonic inhibition by dopamine from the hypothalamus
- Most common cause of hyperprolactinaemia is a prolactinoma
- Drugs such as oestrogen/metoclopramide can cause it
Describe the symptoms of prolactinoma
- Increased prolactin: galactorrhoea (increased milk production in the breast)
- Decreased libido and erectile dysfunction
- Amenorrhoea (menstruation stops)
- Reduced infertility: as prolactin inhibits GnRH
What are the investigations for prolactinoma
- Serum prolactin level: at least 3 measurements
- Thyroid function tests
- MRI of pituitary
What is the treatment for prolactinoma
A dopamine agonist: e.g. cabergoline or bromocriptine (v important to learn)
What are the 4 main examples of non-functioning pituitary tumours
- ) Pituitary adenoma
- ) Cranipharyngioma
- ) Rathke’s cyst
- ) Meningioma
Describe a pituitary adenoma
- Pituitary adenoma’s: make up 10-15% of all tumours that develop in the skull
- Pituitary adenomas can be functioning/non functioning
- Normally slow growing
- 50% are incidentalomas
- Labelled on size: micro + macroadenomas
- Signs of being aggressive:
1. ) Large size
2. ) Cavernous sinus invasion
3. ) Lobular suprasellar margins
Describe a rathke’s cyst
- Derived from Rathke’s pouch: from a single layer of epithelial cells with mucoid/cellular or serous components in the cyst fluid
Describe a meningioma
- Commonest tumour of the region after pituitary adenoma
- Complication of radiotherapy
- Associated with visual disturbance + endocrine dysfunction
