Pituitary tumours are abnormal growths in the pituitary gland, a pea-sized structure at the base of the brain that regulates growth, metabolism, reproduction, and stress response. Most are benign and slow-growing, but their location adjacent to the optic chiasm and their ability to overproduce or suppress hormones means even a small tumour can produce significant systemic and neurological effects. Surgery remains the primary treatment for most symptomatic pituitary tumours, with endoscopic transsphenoidal resection now the standard approach at experienced centres.
According to the neurosurgeon, brain tumor surgery, “pituitary tumours are frequently missed for months or years because the symptoms, weight gain, fatigue, and vision changes, are attributed to unrelated causes before an MRI confirms the diagnosis.”
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What Are the Symptoms of a Pituitary Tumour?
Pituitary tumour symptoms fall into two categories: those caused by mass effect on surrounding structures and those caused by hormonal disruption. Both can be present simultaneously or independently.
Vision Changes: The pituitary gland sits directly below the optic chiasm, and as a tumour grows upward it compresses the crossing visual fibres, producing bitemporal hemianopia, a loss of peripheral vision on both outer sides, that patients often don’t notice until it’s significantly advanced.
Hormonal Overproduction: Functioning tumours secrete excess hormones, with prolactinomas causing irregular periods and galactorrhoea in women and reduced libido in men, growth hormone-secreting tumours producing acromegaly, and ACTH-secreting tumours causing Cushing’s disease with weight gain, stretch marks, and hypertension.
Hormonal Deficiency: Large non-functioning tumours compress the normal pituitary tissue rather than secreting hormones, leading to deficiencies in thyroid, adrenal, and gonadal hormones that present as fatigue, cold intolerance, sexual dysfunction, and infertility without an obvious cause.
Headache: Pituitary tumour headaches are typically bifrontal or bitemporal, often described as a pressure sensation behind the eyes, and in cases of pituitary apoplexy where sudden haemorrhage occurs within the tumour, the headache is severe and of sudden onset requiring emergency intervention.
Symptoms don’t always point to the pituitary first. That delay in diagnosis is what allows many of these tumours to grow undetected for years.
Brain surgery for pituitary tumours is approached through the nose in most cases, avoiding any incision on the skull entirely.
How Is a Pituitary Tumour Diagnosed?
Diagnosis requires a combination of hormonal blood tests and imaging, and the sequence matters because imaging alone doesn’t distinguish between tumour subtypes without biochemical context.
MRI with Contrast: A dedicated pituitary protocol MRI with gadolinium contrast is the first-line imaging investigation, capable of detecting microadenomas under 10mm that wouldn’t appear on standard brain MRI sequences, and it defines tumour size, extension toward the optic chiasm, and invasion of the cavernous sinus.
Hormonal Blood Panel: A full pituitary hormone profile including prolactin, IGF-1, morning cortisol, ACTH, TSH, LH, FSH, and testosterone or oestradiol is ordered in all suspected cases, as hormone levels identify the tumour subtype and determine whether medical management is an option before surgery is considered.
Visual Field Testing: Formal perimetry testing by an ophthalmologist maps the exact extent of visual field loss, establishes a pre-treatment baseline, and is used to monitor recovery of vision after surgical decompression of the optic chiasm according to a best neurosurgeon in India experienced in skull base surgery.
Dynamic Endocrine Testing: When basal hormone levels are borderline, dynamic tests like the dexamethasone suppression test for Cushing’s disease or the oral glucose tolerance test for acromegaly are used to confirm autonomous hormone secretion that doesn’t suppress normally, distinguishing a true functioning tumour from a non-functioning one.
Diagnosis isn’t complete without both imaging and biochemistry. One without the other leads to misclassification and the wrong treatment path.
MRI vs PET Scan: Which Is Better for Brain Tumours? covers how imaging modalities differ in evaluating intracranial tumours including those at the skull base.
How Is Pituitary Tumour Surgery Performed?
Pituitary surgery is one of the more technically precise operations in neurosurgery, largely because of the structures immediately surrounding the gland and the need to preserve normal pituitary function while removing the tumour.
Endoscopic Transsphenoidal Approach: The standard surgical route passes an endoscope through one nostril, through the sphenoid sinus, and directly to the pituitary fossa without any external incision or brain retraction, and this approach provides direct visualisation of the tumour with significantly lower complication rates than older microscopic techniques.
Intraoperative Navigation: Neuronavigation systems map the tumour in three dimensions using pre-operative MRI data, guiding the surgical instruments in real time and reducing the risk of injury to the cavernous sinus, internal carotid artery, and optic nerves that border the operative field on all sides.
Extent of Resection: The surgical goal varies by tumour type. Non-functioning macroadenomas are resected as completely as possible to decompress the optic chiasm and restore vision. Functioning tumours like Cushing’s disease require precise identification and removal of the microadenoma, sometimes a few millimetres in size, with confirmation by intraoperative cortisol measurement.
Post-Operative Monitoring: Patients are monitored closely for diabetes insipidus, hyponatraemia, and adrenal insufficiency in the days following surgery, as transient hormonal disturbances are common after pituitary manipulation and require prompt endocrinological management to avoid serious complications.
Recovery from transsphenoidal surgery is faster than most patients expect. Most are discharged within two to three days, with nasal packing removed before discharge and formal hormonal reassessment at six weeks.
What Is Cortical Mapping in Awake Brain Surgery? explains how intraoperative brain monitoring techniques protect function during complex neurosurgical procedures.
Frequently Asked Questions
Are all pituitary tumours cancerous?
No, the vast majority of pituitary tumours are benign adenomas with no malignant potential.
Can a pituitary tumour be treated without surgery?
Yes, prolactinomas respond well to dopamine agonist medication and often don’t require surgery.
How long does pituitary tumour surgery take?
Most transsphenoidal procedures are completed within two to three hours depending on tumour size.
Will hormones return to normal after pituitary surgery?
Hormone recovery depends on tumour type and duration of compression but improves in most patients.
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