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Genetic and Rare Diseases Information Center (GARD)

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Pseudoangiomatous stromal hyperplasia


* Not a rare disease
Other Names for this Disease
  • Mammary pseudoangiomatous stromal hyperplasia
  • PASH
  • Pseudoangiomatous stromal hyperplasia of the breast
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Your Question

My 20-year-old daughter just had a breast lump removed and the pathology report indicated she has pseudoangiomatous stromal hyperplasia. Although we understand it is a benign condition, we want to learn more about it and are having difficulty finding information. What are the chances that another lump will develop? Is there a link between this condition and the use of birth control pills? If so, does this mean she should not use oral contraceptives in the future?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is pseudoangiomatous stromal hyperplasia (PASH)?

Pseudoangiomatous stromal hyperplasia (PASH) is a type of non-cancerous breast lesion. It typically affects women in the reproductive age group.[1] The size of the lesion varies, but small microscopic PASH is much more common than larger masses. Microscopic PASH is often an incidental finding in breast biopsies done for other non-cancerous or cancerous lesions. Tumorous PASH presents as a firm, painless breast mass or a dense region on a mammogram.[2][1] 
Last updated: 4/8/2011

Are the masses seen in individuals with pseudoangiomatous stromal hyperplasia (PASH) cancerous?

The masses observed in individuals with PASH are benign (non-cancerous) and require diagnosis only to distinguish them from cancerous (malignant) lesions. It may be mistaken for angiosarcoma; however, the breast lesions caused by angiosarcoma are different than those seen in PASH.[3]
Last updated: 7/19/2013

What size are the masses observed in pseudoangiomatous stromal hyperplasia (PASH)?

The size of PASH lesions range from incidental microscopic findings to breast masses that are palpable or evident on a mammogram. Masses are usually large (5–6 cm in diameter), with reported diameters ranging from 1 to 12 cm. The masses may grow over time.[2]
Last updated: 7/19/2013

Who is diagnosed with pseudoangiomatous stromal hyperplasia (PASH)?

PASH most commonly affects premenopausal women. The age range of people diagnosed with PASH is 14-67 years; however, most individuals are diagnosed in their late thirties or forties.[2]
Last updated: 7/19/2013

Is treatment available for pseudoangiomatous stromal hyperplasia (PASH)?

Surgical removal of the PASH lesions has been performed in some individuals. A wide margin around the mass may be removed to prevent recurrence. Although PASH lesions often grow over time and may recur, they are neither associated with malignancy (cancer) nor considered to be premalignant (pre-cancerous).[2] According to the medical text, CONN's Current Therapy 2007, approximately 7 percent of people experience a recurrence of PASH.[3]
Last updated: 7/19/2013

Is there a link between pseudoangiomatous stromal hyperplasia (PASH) and the use of birth control pills? If so, does this mean a person should not use oral contraceptives in the future?

In one study, 50% (13 out of 26 individuals) had a history of using oral contraceptives or hormone replacement therapy.[4] Although PASH lesions often occur in patients on hormone therapy, the role hormones play is unclear.[3] Individuals with PASH should discuss further use of oral contraceptives or other hormone therapy with their personal health care provider.
Last updated: 7/19/2013

  • Virk RK, Khan A. Pseudoangiomatous stromal hyperplasia: an overview. Arch Pathol Lab Med. 2010 Jul;
  • Cyrlak D, Carpenter PM. Breast imaging case of the day: Pseudoangiomatous stromal hyperplasia. Radiographics. 1999; 19:1086-1088. Accessed 3/4/2008.
  • Sukumvanich P, Borgen P. Diseases of the Breast. In: Rakel RE, Bope ET. CONN'S Current Therapy 2007, 59th ed. Philadelphia, PA: Saunders Elsevier; 2007..
  • Ferreira M, Albarracin CT, Resetkova E. Pseudoangiomatous stromal hyperplasia tumor: a clinical, radiologic and pathologic study of 26 cases. Mod Pathol. 2008 Feb;21(2):201-7. PubMed.