16th September 2024

Non-functioning pituitary tumours

Non-functioning adenomas (NFA) are pituitary tumours that do not cause hypersecretory syndromes (GH excess, hypercortisolism, hyperprolactinaemia). Approximately one third of pituitary adenomas are categorised as non-functioning. The majority are macroadenomas, often detected incidentally during MRI scans for other reasons.

Clinical features

NFAs can cause pituitary hypofunction due to compression of pituitary tissue and symptoms from the local mass effect. Hyperprolactinemia may occur if the adenoma compresses the pituitary stalk, reducing hypothalamic dopamine and increasing prolactin. A concise summary of clinical features is provided in the table below.

Investigations

A complete pituitary hormone profile should be checked to check hypopituitarism and if there is hyperprolactinaemia. If not already performed, an MRI of the pituitary gland to determine the extent of the tumour and how it affects the surrounding structures. Formal visual field testing to assess the visual field defects due to compression of the optic chiasm.

Management

Initial treatment involves transsphenoidal surgery, followed by blood tests, visual field testing and repeat imaging to monitor for tumour regrowth and adequacy of hormone replacement therapy. Radiotherapy is often used post-surgery to slow tumour growth. Complications from radiotherapy include hypopituitarism and neurological deficits.

References

• Snyder P. Clinical manifestations and diagnosis of gonadotroph and nonfunctioning pituitary adenomas [Internet]. Cooper D, Martin K, editors. UpToDate. 2024. Available from: https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-gonadotroph-and-nonfunctioning-pituitary-adenomas#H177771375
• Snyder P. Treatment of gonadotroph and other clinically nonfunctioning adenomas [Internet]. Cooper D, Martin K, editors. UpToDate. 2023. Available from: https://www.uptodate.com/contents/treatment-of-gonadotroph-and-other-clinically-nonfunctioning-adenomas#H8