What is pituitary gland cancer?
The pituitary gland is in your head. It makes
Cells in the pituitary gland sometimes change and no longer grow or behave normally. These changes may lead to pituitary gland cancer. Almost all pituitary gland cancers are pituitary neuroendocrine tumours (PitNETs). So when people talk about pituitary gland cancer, they usually mean PitNETs. But sometimes rare types of pituitary gland tumours can develop.
Pituitary neuroendocrine tumours (PitNETs)
PitNETs used to be called pituitary adenomas. Doctors thought that these tumours were non-cancerous (benign) because they grow slowly and don’t usually spread. But PitNETs are now considered cancerous because even slow-growing tumours may spread over time.
Most PitNETs start in the front (anterior) part of the pituitary gland. These tumours are usually classified by the size of the tumour, as well as which nearby tissues it has grown into (invaded) and how deep it has grown into them. PitNETs can grow into the sphenoid bone in the skull, the brain, the nerve that connects the eyes to the brain (called the optic nerve) and the nasal sinuses.
PitNETs are also classified as functioning or non-functioning.
Functioning tumours make too much of a certain hormone, which causes symptoms. Most PitNETs are functioning tumours. They are named based on the type of hormone they make:
- prolactin-producing tumour (also called a prolactinoma)
- growth hormone–producing tumour (also called somatotroph adenoma)
- adrenocorticotropic hormone (ACTH)–producing tumour (also called corticotroph adenoma)
- thyroid-stimulating hormone (TSH)–producing tumour (also called thyrotroph adenoma)
- gonadotropin-producing tumour (also called gonadotroph adenoma)
Non-functioning tumours don’t make hormones. They can cause symptoms when they grow large and press on the pituitary gland and nearby tissues in the brain.
Metastatic PitNETs
In rare cases, PitNETs can spread (metastasize) to other parts of the body. If they do spread, they are called metastatic PitNETs. (Metastatic PitNETs used to be called pituitary carcinoma.)
It’s much more common for cancer to spread to the pituitary gland than for PitNETs to spread to other parts of the body. Cancer that starts in another part of the body and spreads to the pituitary gland is not the same as and is treated differently than PitNETs. Find out more about metastasis.
Rare pituitary gland tumours
In rare cases, tumours that aren’t PitNETs can develop in the pituitary gland:
- Rathke cleft cysts are benign (non-cancerous) fluid-filled sacs that form between the back (posterior) and front (anterior) parts of the pituitary gland.
-
Pituicytomas are benign tumours made of specialized
glial cells (called pituicytes) in the back part of the pituitary gland. - Pituitary blastoma is a very rare type of pituitary gland cancer found in young children.
The pituitary gland
Your trusted source for accurate cancer information
With support from readers like you, we can continue to provide the highest quality cancer information for over 100 types of cancer.
We’re here to ensure easy access to accurate cancer information for you and the millions of people who visit this website every year. But we can’t do it alone.
Every donation helps fund reliable cancer information, compassionate support services and the most promising research. Please give today because every contribution counts. Thank you.