Which initial investigations should be conducted in a patient suspecte

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Initial investigations for a patient suspected of having a pituitary adenoma should include:

Hormonal blood tests to assess pituitary function and identify hormone hypersecretion or hypopituitarism, including serum cortisol (preferably 8 am to 9 am), thyroid function tests, prolactin, growth hormone/IGF-1, and gonadotropins. This helps detect functional adenomas or pituitary insufficiency ,.
Magnetic Resonance Imaging (MRI) of the pituitary with contrast is the imaging modality of choice to visualize the adenoma, determine its size, and assess for local invasion or compression of surrounding structures .
Visual field assessment

These investigations guide diagnosis, management, and referral to endocrinology or neurosurgery as appropriate.

Which initial investigations should be conducted in a patient suspected of having a pituitary adenoma?