Clinically non functioning pituitary tumours may be null cell adenomas or have positive staining for other peptides but with no clinically detectable sequelae. Diagnosis requires MRI scanning and assessment of pituitary function.
Start appropriate therapy immediately if hypopituitarism is confirmed.
Arrange dynamic pituitary function testing with insulin or glucagon stress testing. Arginine-GHRH testing is an appropriate alternative for GH deficiency if insulin testing is contraindicated. Similarly, Synacthen testing is also occasionally used in patients with suspected chronic ACTH deficiency if the insulin stress test is contraindicated, though this may be unreliable in patients wtih pituitary disease.
It is usually possible to differentiate between a NFPA and prolactinoma clinically. However, in certain difficult cases, consider instituting a trial of medical therapy with close monitoring of visual fields, serum prolactin and MRI appearance.
Visual fields and MRI appearances should respond rapidly and dramatically in the case of a macroprolacinoma, with a smooth decline in serum prolactin.
Visual fields and MRI appearance will not change but there may be a massive immediate fall in prolactin with a NFPA since the prolactin emanates from normal not tumourous cells in this case.
If clinical doubt remains, and vision is threatened, early surgery should be considered.
If clinical features are unusual for example with a suprasellar or peripituitary mass on MRI scan, or with diabetes insipidus, consider other causes. Ensure that serum angiotensin converting enzyme, ESR, auto-antibody screen, alpha feto protein, human choriotropic hormone and chest radiograph have all been assessed before discussing at a multidisciplinary meeting to determine further management.
Review MRI scan, visual field testing and other results before deciding on conservative management or surgery. Consider urgent surgical referral in all cases with visual field involvement.
For incidental pituitary lesions, a conservative approach is often appropriate.
All new non functioning pituitary tumours require discussion at a pituitary MDT.
The presence of a visual field defect mandates the consideration of surgery in all cases. Impingement of the optic chiasm should also prompt consideration of early surgery, although patient factors must be considered, and conservative management with close monitoring of tumour size on serial MRI scan and of visual fields may be suitable in selected cases.
However, conservative management is frequently suitable for small incidental lesions after discussion.
Repeat MRI at three to six months post-operatively according to multidisciplinary discussion.
Consider further surgery or radiotherapy if a significant disease remnant is visible on the initial post operative MRI scan, if the histology has particularly concerning features eg a high Ki67 index, or for a growing tumour remnant during serial imaging post surgery.
There is also some evidence for tumour stablisation with dopamine agonist use. This may be considered in aggressive or growing tumours following conventional treatment with surgery and or radiotherapy, or in patients unfit for surgery.
Clinical review with repeat assessment of pituitary function (basal +/- dynamic if necessary), visual fields and optimisation of pituitary replacement therapy is necessary at three, six and 12 months post-operatively.
MRI scans tend to be repeated at three to six months post op, then at one year, then at three years and then at three-yearly intervals if surgical clearance is satisfactory.
Always repeat MRI scan sooner if there is a clinical indication, for example a new headache, visual field or acuity loss.
Patients who have responded well to surgery and radiotherapy may not need such regular scanning.
Repeat basal pituitary function in all patients annually, with alternative year dynamic testing to seek GH and ACTH deficiency in patients who have undergone radiotherapy.
Ensure thyroxine levels are between the middle and upper end of the reference range.
Ensure patient is not clinically or biochemically over-replaced with glucocorticoid, and ensure that sex hormone and GH replacement therapy have been considered.
Monitor and treat cardiovascular risk factors aggressively.
Monitor and treat new cerebrovascular disease or new tumours.
Consider repeat surgery, radiosurgery or radiotherapy if regrowth or recurrent tumour detected after initial surgery and radiotherapy. Dopamine agonist therapy may also be considered in this group as there is some evidence of tumour stabilisation, and the treatments are generally well tolerated.