Breast cysts

Last updated: June 13, 2023

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Summarytoggle arrow icon

Breast cysts are circumscribed fluid collections that most commonly occur in premenopausal women. The typical presentation includes single or multiple breast masses of variable size that may be tender. Because cysts cannot be reliably distinguished from a solid mass on palpation or mammography, the diagnostic evaluation requires a breast ultrasound. Based on ultrasound findings, breast cysts are characterized as simple, complicated, or complex. Complex breast cysts are associated with an increased risk of malignancy and should be biopsied. Complicated breast cysts are typically benign; a biopsy should be considered if there is clinical suspicion of malignancy. Simple breast cysts are benign and seldom require any further diagnostics. Management depends on the type of cyst and risk of malignancy and includes surveillance, therapeutic aspiration, and surgical excision.

Epidemiologytoggle arrow icon

Epidemiological data refers to the US, unless otherwise specified.

Clinical featurestoggle arrow icon

  • Maybe asymptomatic (detected incidentally) [3]
  • Single or multiple breast masses
  • May be tender
  • Variable size (microcysts, gross cysts, clusters) and texture (smooth, soft, firm)
  • Usually mobile

Cystic and solid breast masses cannot reliably be distinguished on physical examination alone. [2][4][5]

Managementtoggle arrow icon

Approach [2][5]

Ultrasound is the preferred modality for differentiating between cystic and solid breast masses. [2][6][7]

Biopsy is recommended for all breast cysts with suspicious features (e.g., doppler flow, thick septations or walls, solid components). [6]

Cytological evaluation is recommended if bloody fluid is obtained on therapeutic or diagnostic aspiration. [2][3]

Characterization of breast cysts [2][5][8]

Breast cysts are best characterized on ultrasound. On mammography, a breast cyst appears as a round, circumscribed mass (i.e., indistinguishable from a solid breast mass). [2][5]

Types of breast cysts [2][3][8]
Simple breast cyst Complicated breast cyst Complex breast cyst
Characteristic features on ultrasound
  • Round well-defined mass with any of the following:
    • Internal septations
    • Mural thickening
    • Thick walls
    • Solid and cystic components
Risk of malignancy
  • None
  • Low (< 2%) [2][8]
  • High (up to 23%) [8]

Mammography cannot reliably distinguish between a solid and cystic breast mass. A breast mass detected on mammography should be additionally evaluated on ultrasound. [2][5][6]

Management of simple breast cysts [2][3]

  • Asymptomatic cysts: : no intervention required; most resolve spontaneously [9]
  • Symptomatic cysts : Consider ultrasound-guided fine needle aspiration. [2][6]
    • Simple cysts generally collapse on aspiration.
    • Aspirate is typically serous and can be discarded.

Simple breast cysts are not associated with an increased risk of breast cancer. Routine breast cancer screening is appropriate. [2][3][8]

Management of complicated breast cysts [2][3][6][8]

Management depends on patient preferences and clinical concern for malignancy and includes the following.

Routine breast cancer screening is appropriate for patients with complicated breast cysts that have been proven benign on biopsy or have not increased in size over a period of surveillance. [8]

Management of complex breast cysts [2][3][8]

Perform an ultrasound-guided core needle biopsy or excisional biopsy in all patients. [2][6]

Referencestoggle arrow icon

  1. Moy L, Heller SL, Bailey L, et al. ACR Appropriateness Criteria ® Palpable Breast Masses. J Am Coll Radiol. 2017; 14 (5): p.S203-S224.doi: 10.1016/j.jacr.2017.02.033 . | Open in Read by QxMD
  2. ACOG. Practice Bulletin No. 164 Diagnosis and management of benign breast disorders. Obstetrics & Gynecology. 2016; 127 (6): p.e141-e156.doi: 10.1097/aog.0000000000001482 . | Open in Read by QxMD
  3. Hooley RJ, Scoutt LM, Philpotts LE. Breast Ultrasonography: State of the Art. Radiology. 2013; 268 (3): p.642-659.doi: 10.1148/radiol.13121606 . | Open in Read by QxMD
  4. Dodelzon K, Katzen JT. Evaluation of Palpable Breast Abnormalities. J Breast Imaging. 2019; 1 (3): p.253-263.doi: 10.1093/jbi/wbz040 . | Open in Read by QxMD
  5. Pleasant V. Management of breast complaints and high-risk lesions. Best Practice & Research Clinical Obstetrics & Gynaecology. 2022; 83: p.46-59.doi: 10.1016/j.bpobgyn.2022.03.017 . | Open in Read by QxMD
  6. Bevers TB, Helvie M, Bonaccio E, et al. Breast Cancer Screening and Diagnosis, Version 3.2018, NCCN Clinical Practice Guidelines in Oncology. Journal of the National Comprehensive Cancer Network. 2018; 16 (11): p.1362-1389.doi: 10.6004/jnccn.2018.0083 . | Open in Read by QxMD
  7. Rao R, Ludwig K, Bailey L, et al. Select Choices in Benign Breast Disease: An Initiative of the American Society of Breast Surgeons for the American Board of Internal Medicine Choosing Wisely® Campaign. Ann Surg Oncol. 2018; 25 (10): p.2795-2800.doi: 10.1245/s10434-018-6584-5 . | Open in Read by QxMD
  8. $Contributor Disclosures - Breast cysts. None of the individuals in control of the content for this article reported relevant financial relationships with ineligible companies. For details, please review our full conflict of interest (COI) policy:.
  9. Lucas JH, Cone DL. Breast cyst aspiration.. Am Fam Physician. 2003; 68 (10): p.1983-6.

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