Pituitary Tumor Symptoms: What to Know About Pituitary Adenomas

What is the pituitary gland and what does it control?

The pituitary gland sits just below the brain in a bony cavity called the sella turcica, directly above the optic chiasm — where the optic nerves from both eyes cross. It is sometimes called the "master gland" because it secretes hormones that regulate other glands throughout the body:

• ACTH — stimulates cortisol production from the adrenal glands
• TSH — stimulates the thyroid gland
• LH and FSH — regulate reproductive function and sex hormones
• GH (growth hormone) — affects growth and metabolism
• Prolactin — stimulates milk production
• ADH and oxytocin — control water balance and uterine contractions (stored and released from the posterior pituitary)

When a tumor grows in or near the pituitary, it can disrupt any of these systems 1Ref 1Shafiq I, Anastasopoulou C (2025).Pituitary Adenoma.Classification of pituitary adenomas by size (micro/macro) and function; prolactinomas as the most common type (~50% of clinically relevant cases); transsphenoidal surgery as first-line treatment. Pituitary adenomas account for roughly 15% of all intracranial tumors, making them among the most common brain tumors.

What symptoms does a pituitary tumor cause?

Symptoms fall into two broad categories: those caused by the tumor pressing on nearby structures, and those caused by hormone abnormalities.

Mass effect — pressure from the tumor: - Headaches — often a dull, persistent ache behind the eyes or at the top of the head - Visual field changes — the optic chiasm sits directly above the pituitary; a growing tumor can compress it, causing loss of peripheral (side) vision. The classic pattern is "bitemporal hemianopia" — loss of the outer visual fields in both eyes, which may go unnoticed because central vision is initially preserved 2Ref 2Freda PU, Beckers AM, Katznelson L, Molitch ME, Montori VM, Post KD, Vance ML; Endocrine Society (2011).Pituitary incidentaloma: an endocrine society clinical practice guideline.Evaluation and monitoring approach for incidentally discovered pituitary adenomas: MRI, hormone testing, visual field assessment, and surveillance intervals - Double vision or drooping eyelid — if the tumor extends laterally and affects nerves controlling eye movement

Hormonal excess — depending on which hormone the tumor overproduces: - Prolactinoma (most common type — about half of all secretory adenomas 1Ref 1Shafiq I, Anastasopoulou C (2025).Pituitary Adenoma.Classification of pituitary adenomas by size (micro/macro) and function; prolactinomas as the most common type (~50% of clinically relevant cases); transsphenoidal surgery as first-line treatment3Ref 3Petersenn S, Fleseriu M, Casanueva FF, Giustina A, et al. (2023).Diagnosis and management of prolactin-secreting pituitary adenomas: a Pituitary Society international Consensus Statement.Prolactinomas as the most common secretory pituitary tumor; dopamine agonists (cabergoline, bromocriptine) as first-line medical treatment; irregular menses and galactorrhea as cardinal symptoms): irregular or absent periods in women, unexplained breast milk production (galactorrhea), reduced libido, infertility - Acromegaly (GH-secreting): gradual enlargement of hands, feet, and facial features; joint pain; increased sweating - Cushing's disease (ACTH-secreting): central weight gain, easy bruising, stretch marks, high blood pressure, and high blood sugar — driven by excess cortisol 4Ref 4Fleseriu M, Auchus R, Bancos I, et al. (2021).Consensus on Diagnosis and Management of Cushing's Disease: A Guideline Update.Cushing's disease caused by ACTH-secreting pituitary adenoma; characteristic features include central weight gain, easy bruising, hypertension, and hyperglycemia; transsphenoidal surgery is first-line treatment - TSH-secreting tumor (rare): symptoms of overactive thyroid — rapid heartbeat, weight loss, heat intolerance

What if the tumor does not make hormones?

Some pituitary adenomas are "non-functioning" — they do not produce excess hormones and are often discovered incidentally on an MRI done for another reason (these are called incidentalomas). Non-functioning tumors tend to grow slowly and may cause no symptoms for years. When they become large enough to press on surrounding structures, the mass-effect symptoms above emerge.

An incidentally discovered pituitary tumor requires periodic monitoring with MRI and hormone testing to watch for growth or hormonal change 2Ref 2Freda PU, Beckers AM, Katznelson L, Molitch ME, Montori VM, Post KD, Vance ML; Endocrine Society (2011).Pituitary incidentaloma: an endocrine society clinical practice guideline.Evaluation and monitoring approach for incidentally discovered pituitary adenomas: MRI, hormone testing, visual field assessment, and surveillance intervals. The Endocrine Society guideline provides specific surveillance intervals based on tumor size.

How is a pituitary adenoma diagnosed?

Diagnosis typically combines:

• MRI of the pituitary with contrast — the imaging test of choice; identifies the tumor's size and location. Tumors under 10 mm are called microadenomas; 10 mm or larger are macroadenomas 1Ref 1Shafiq I, Anastasopoulou C (2025).Pituitary Adenoma.Classification of pituitary adenomas by size (micro/macro) and function; prolactinomas as the most common type (~50% of clinically relevant cases); transsphenoidal surgery as first-line treatment
• Blood tests — measuring pituitary hormones (prolactin, IGF-1 for growth hormone assessment, cortisol, TSH, LH, FSH) and the hormones they regulate in peripheral glands 2Ref 2Freda PU, Beckers AM, Katznelson L, Molitch ME, Montori VM, Post KD, Vance ML; Endocrine Society (2011).Pituitary incidentaloma: an endocrine society clinical practice guideline.Evaluation and monitoring approach for incidentally discovered pituitary adenomas: MRI, hormone testing, visual field assessment, and surveillance intervals
• Visual field testing — a formal ophthalmological test mapping peripheral vision to detect optic chiasm compression 2Ref 2Freda PU, Beckers AM, Katznelson L, Molitch ME, Montori VM, Post KD, Vance ML; Endocrine Society (2011).Pituitary incidentaloma: an endocrine society clinical practice guideline.Evaluation and monitoring approach for incidentally discovered pituitary adenomas: MRI, hormone testing, visual field assessment, and surveillance intervals

Some tumors are found during workup for infertility, irregular periods, or unexplained headaches — making hormone evaluation an essential part of the diagnostic chain.

Who treats pituitary adenomas?

This is a multispecialty condition managed by a team:

• Endocrinologist — evaluates and manages the hormonal aspects; medical treatment for prolactinomas uses dopamine agonists (cabergoline or bromocriptine), which are usually first-line and often shrink the tumor 3Ref 3Petersenn S, Fleseriu M, Casanueva FF, Giustina A, et al. (2023).Diagnosis and management of prolactin-secreting pituitary adenomas: a Pituitary Society international Consensus Statement.Prolactinomas as the most common secretory pituitary tumor; dopamine agonists (cabergoline, bromocriptine) as first-line medical treatment; irregular menses and galactorrhea as cardinal symptoms
• Neurosurgeon — performs surgery when needed, typically through the nose (transsphenoidal approach), without opening the skull 1Ref 1Shafiq I, Anastasopoulou C (2025).Pituitary Adenoma.Classification of pituitary adenomas by size (micro/macro) and function; prolactinomas as the most common type (~50% of clinically relevant cases); transsphenoidal surgery as first-line treatment
• Ophthalmologist — monitors visual fields if the tumor is near the optic chiasm 2Ref 2Freda PU, Beckers AM, Katznelson L, Molitch ME, Montori VM, Post KD, Vance ML; Endocrine Society (2011).Pituitary incidentaloma: an endocrine society clinical practice guideline.Evaluation and monitoring approach for incidentally discovered pituitary adenomas: MRI, hormone testing, visual field assessment, and surveillance intervals
• Radiation oncologist — involved in some cases where surgery is incomplete or the tumor is aggressive

For emergency situations — sudden vision loss, severe headache — go to an emergency department directly. A Gale clinician can help you understand symptoms that may suggest a pituitary problem, order initial hormone bloodwork, and refer you to an endocrinologist.