Treatment of Non-Functional Pituitary Tumors (Tumors That Don’t Make Excess Hormones)

Some pituitary adenomas don’t make enough excess hormones for them to cause symptoms. Most of these non-functional pituitary tumors are gonadotroph adenomas that don’t make enough hormones to cause any problems.

Not all of these tumors need to be treated right away, especially if they're small and not growing or causing symptoms. But large tumors and those that are clearly growing often do need treatment.

Large pituitary tumors (macroadenomas)

Most non-functioning pituitary tumors grow large enough to cause local symptoms such as vision problems or headaches before they are found. They might also cause symptoms by pressing on the normal parts of the pituitary, which can lead to lower levels of pituitary hormones. 

These macroadenomas are most often treated with surgery if it can be done. The goal of surgery is to remove as much of the tumor as possible. This can usually help relieve any symptoms the tumor is causing and can lower the chances the tumor will come back and cause problems in the future. Some macroadenomas can be removed completely, but this might not be possible for other tumors, based on their size and location.

If the tumor can’t be removed completely, if it comes back after surgery, or if a person can’t have surgery for some reason, radiation therapy might be done. Radiation tends to work very slowly (over many months), so it’s not usually the first treatment tried, especially in people who are having symptoms. Because radiation works slowly, medicines might be tried in the meantime to help relieve any symptoms the tumor is causing, although drugs aren’t always helpful for non-functioning tumors (see below).

MRI scans typically are done for many years after treatment. Eye exams and blood tests of hormone levels may be done, too. If the tumor comes back, more surgery or radiation may be used.

Medicines are not usually not helpful in treating non-functioning tumors, but some of the same drugs used when treating functioning pituitary tumors may be tried if surgery and radiation therapy aren't good options. Some doctors have reported success using the chemotherapy drug temozolomide for fast-growing tumors.

Pituitary incidentalomas

These are pituitary tumors that are seen on scans of the head done for other reasons. Many of these are smaller tumors (microadenomas), but some of them are larger (macroadenomas). These tumors usually don't cause obvious symptoms because they're not big enough to press on nearby structures and they don't make excess levels of any hormone.

For larger incidentalomas, tests and exams are often done to see if the tumor is making any excess hormones, or if it is causing subtle symptoms that a person might not be aware of. If either of these is true, then treatment is often recommended. (See above or Treatment of Functional (Hormone-Making) Pituitary Tumors.) Otherwise, the tumor often can be watched closely over time with MRIs to see if it is growing.

Smaller incidentalomas usually do not change over time, and doctors often recommend just watching them with regular MRI scans to see if the tumor starts growing. Hormone levels may be checked, too, although not all doctors agree in which ones should be checked or how often. If the tumor does start growing or causing symptoms, it can then be treated. But it's important to find the right balance so that people with incidentalomas aren't getting tests or treatments that they don't really need.