Short answer · Medically reviewed summary · Last updated: 2026-05-08
A pituitary tumour is an abnormal growth of cells within the pituitary gland, a pea-sized organ at the base of the brain that regulates essential hormones throughout the body. While most are benign (non-cancerous) adenomas, they can significantly impact health by either overproducing hormones or physically pressing on surrounding brain structures. What are the main types of pituitary tumour? Clinicians classify a pituitary tumour based on its size and whether it produces excess hormones.
What is Pituitary tumour
What is Pituitary tumour? Plain-language, medically reviewed definition plus the lived reality told by patients.
A pituitary tumour is an abnormal growth of cells within the pituitary gland, a pea-sized organ at the base of the brain that regulates essential hormones throughout the body. While most are benign (non-cancerous) adenomas, they can significantly impact health by either overproducing hormones or physically pressing on surrounding brain structures.
What are the main types of pituitary tumour?
Clinicians classify a pituitary tumour based on its size and whether it produces excess hormones. "Microadenomas" are smaller than 10mm, while "macroadenomas" are 10mm or larger. Functioning tumors secrete hormones that lead to specific conditions like Cushing’s disease or acromegaly, whereas non-functioning tumors do not produce excess hormones but may cause vision changes or headaches due to their size.
Who is typically affected by a pituitary tumour?
Research suggests that pituitary tumour cases are more common than previously thought, with autopsy studies indicating that up to 10–20% of the general population may harbor a small, asymptomatic growth. These tumors can occur at any age, though they are most frequently diagnosed in adults between the ages of 30 and 60. There is no significant gender bias for general adenomas, although specific hormonal subtypes may show varying distributions.
How does a pituitary tumour affect the body?
Because the pituitary gland acts as the "master gland," a pituitary tumour can disrupt multiple systems. Common physiological impacts include:
- Hormonal Imbalance: Excess or deficiency in growth hormone, prolactin, ACTH, or TSH.
- Neurological Pressure: Compression of the optic nerves, leading to "bitemporal hemianopsia" (loss of peripheral vision).
- Metabolic Changes: Unexplained weight gain, fatigue, or changes in blood pressure.
- Reproductive Issues: Irregular menstrual cycles or loss of libido.
Is a pituitary tumour hereditary?
While the vast majority of pituitary tumour cases occur sporadically (without a family history), a small percentage are associated with genetic syndromes such as Multiple Endocrine Neoplasia type 1 (MEN1) or Carney complex. If you have a family history of endocrine tumors, genetic counseling is recommended to assess your risk.
Next steps
- Consult an endocrinologist to evaluate your hormone levels.
- Request an MRI of the brain if you experience persistent headaches or vision changes.
- Join the 97 members on DiseaseMaps.org to share experiences with others living with a pituitary tumour.
Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician.
References
- NIH Genetic and Rare Diseases Information Center (GARD): Pituitary Adenoma
- Orphanet: Pituitary adenoma
- Pituitary Foundation: Understanding your pituitary condition
- PubMed/NCBI: Epidemiology and clinical management of pituitary tumors
