Pseudoangiomatous Stromal Hyperplasia (PASH)

Learn about PASH - a benign (non-cancer) breast condition - including symptoms, diagnosis and treatment.

1. What is PASH (Pseudoangiomatous Stromal Hyperplasia)?

PASH is a benign (not cancer) breast condition.

It’s more common in premenopausal women - women who haven’t been through the menopause. But it can affect women of any age. PASH can also affect men, but this is rare.

It’s not known what causes PASH, but it’s thought it might be linked to hormonal changes in the body.

2. What are the symptoms of PASH?

In premenopausal women, PASH on its own is usually felt as a painless lump in the breast. The size of the lump can vary.

In post-menopausal women (women who have been through the menopause), PASH may be found by chance during a routine screening mammogram.

PASH can also be found by chance at the same time as other benign breast conditions.

3. How is PASH diagnosed?

PASH is diagnosed using a range of tests. These may include:

  • A
  • An
  • A (several tissue samples may be taken at the same time)
Breast Cancer Now logo with strapline (DIGITAL/SCREEN USE)
Healthcare Information

Mammogram and breast ultrasound

Learn about breast x-rays (mammograms), breast ultrasound and other types of imaging used to detect breast changes, and what to expect at yo...

4. How is PASH treated?

In most cases you won’t need any treatment or follow-up if you have PASH. Usually you’ll only be asked to go back to your GP or the breast clinic if have a lump and it gets bigger or you notice a change.

If the area of PASH is large or gets bigger, you may need an excision . This will usually be done under general anaesthetic.

5. Does PASH increase my risk of breast cancer?

Having PASH does not increase the risk of developing breast cancer.

It’s important to continue to be breast aware, and to go back to your GP if you notice any changes in your breasts, however soon this is after your diagnosis of PASH.

A young woman with long curly black hair wearing a light blue vest, checks her under arm breast area in the mirror
Healthcare Information

Signs and symptoms of breast cancer

Breast cancer can cause a number of signs and symptoms. See your GP if you notice a change to your breast that’s new or unusual for you.

6. Further support

Having PASH may make you feel anxious and in need of further support.

If you have any questions about PASH or would just like to talk it through with an expert, you can call our free helpline - see below.

Was this helpful?

Was this helpful?
Please tell us what you liked about it.
Please tell us why.
We’re sorry you didn’t find this helpful.
Please do not include personal details and be aware we cannot respond to comments.

Quality assurance

Last reviewed in August 2020. The next planned review begins in February 2023.

  • support-cta-icon-telephone

    Call our free helpline

    If you have any concerns about breast cancer, or just want to talk, our specialist nurses are here for you.

    Lines open: Monday to Friday - 9am to 4pm; Saturday - 9am to 1pm

  • support-cta-icon-email

    Explore ways to talk to our nurses

    It can be difficult to talk to someone in person about breast cancer concerns. Explore other ways you can ask a question.

Share this page