Pituitary microadenoma: Meaning in a Radiology Report

Pituitary microadenoma

Also written as: microadenoma, pituitary adenoma, PitNET

A pituitary microadenoma is a small benign growth in the pituitary gland, under 10 mm across. It is common and often found by chance.

Seen on: MRI

How it reads in a report

A 5 mm hypoenhancing lesion in the left side of the pituitary gland on dynamic contrast images, consistent with a pituitary microadenoma.

What it means

The pituitary is a pea-sized gland under the brain that controls many of the body's hormones. A microadenoma is a small, non-cancerous growth of its cells, under 10 mm across. On MRI it usually appears as a small spot that takes up contrast dye more slowly than the normal gland. Some make extra hormone, but many make none.

When it matters

Small pituitary spots turn up fairly often on brain MRI, and most never cause trouble. What matters most is hormone function, so your doctor may order blood tests, for example for prolactin. A microadenoma that makes too much hormone can cause symptoms such as irregular periods or milky nipple discharge, and may need treatment. One that makes no hormone is often rechecked with a later MRI.

Questions to ask your doctor

Should my hormone levels be checked with blood tests?
When should the MRI be repeated, if at all?
Could it be the cause of any hormone-related symptoms I have?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.