Trusted medical expertise in seconds.

Access 1,000+ clinical and preclinical articles. Find answers fast with the high-powered search feature and clinical tools.

Try free for 5 days
Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer.

Benign breast conditions

Last updated: May 26, 2021

Summarytoggle arrow icon

There are a number of benign conditions that can affect the breasts, including congenital anomalies (e.g., supernumerary nipples), fat necrosis, mastitis, fibrocystic changes, gynecomastia, mammary ductal ectasia, and neoplasms such as fibroadenoma, phyllodes tumor, and intraductal papilloma. Fibrocystic changes result in the most common benign lesion of the breast, and, like the rest of these lesions, primarily affect women between the third and fifth decades of life. Although benign breast conditions may cause symptoms that mimic breast cancer, the majority of these lesions do not increase the risk of malignant disease. They are usually diagnosed with ultrasound and mammogram, but in some cases biopsy is required. Because of the benign character of these conditions, treatment does not generally involve surgery.

Overview of benign breast conditions
Disorder Epidemiology [1] Clinical features Diagnostics Treatment
Congenital anomalies of the breast
  • Affect 1–6% of the general population [2]
  • Clinical
  • Surgical correction
Fibrocystic changes
  • Most common benign lesion of the breast
  • Premenstrual breast tenderness
  • Multiple breast nodules bilaterally
  • Most common in nursing mothers
  • Clinical
Fat necrosis
  • Unnecessary
  • Most common benign breast lesion in lactating women
  • Frequently occurs during or after lactation
  • Painless, firm mass
  • Repeated needle aspiration or surgical excision if cysts are symptomatic


  • Firm, concentric mass at the nipple-areolar complex, which may be tender
  • Mainly clinical
  • Mammogram (in ambiguous cases)
  • Only required in persistent cases
  • Medical therapy: testosterone replacement or tamoxifen
  • Surgery (subcutaneous mastectomy)
  • Treatment of the underlying cause
  • Most common breast mass in women < 35 years
  • Solitary, well-defined, non-tender, rubbery, and mobile mass
  • Regular check-ups
Phyllodes tumor
  • Painless, smooth, multinodular lump
  • Variable growth rate
  • Generally > 3 cm
  • Surgical excision
Intraductal papilloma
  • Peak incidence
    • Solitary lesions: ∼ 48 years
    • Multiple lesions: ∼ 41 years
  • Surgical excision
Mammary duct ectasia
  • Usually unnecessary
  • Antibiotic therapy if infected
  • Surgical excision for persistent lesions

The mammary ridge regresses in the 7th–8th week of embryonal development. Disorders during this stage of development may lead to the following anomalies:

  • Amastia: absence of breast tissue and nipples
  • Polymastia: presence of accessory breast tissue
  • Athelia: absence of nipples
  • Polythelia: presence of accessory nipples
  • Poland syndrome [3]
    • Unilateral aplasia/hypoplasia of the pectoralis muscles and breast with associated fingers abnormalities (e.g., brachysyndactyly)
    • Most commonly develops on the right side


  • Definition: benign changes characterized by the formation of fibrotic and/or cystic tissue [4][5]
  • Epidemiology
    • Most common benign lesion of the breast
    • Primarily in premenopausal women 20–50 years of age
    • Up to 50% of women are affected during their lifetime.
  • Etiology: unknown

Histologic subtypes [6]

Clinical features

Diagnostics [8]

  • Physical exam
  • Ultrasound and mammogram (first-line)
    • Ultrasound
      • Findings range from normal appearance to focal regions of thick parenchyma.
      • Сysts may be present.
    • Mammogram (not recommended for women < 30 years)
      • Round or oval masses with clear borders
      • In some cases, dispersed calcifications
  • Fine-needle aspiration (after imaging confirms a cystic lesion): indicated if the patient is symptomatic and/or requests the procedure
  • Biopsy: confirms diagnosis if imaging is inconclusive

Treatment [9]


Depends on the histologic subtype:

  • Nonproliferative lesions do not increase the risk of cancer.
  • Proliferative lesions with atypical cells (e.g., ductal epithelial hyperplasia) are associated with an increased risk of cancer.

Patients with mastitis should continue breastfeeding to reduce the risk of a breast abscess.

Breast abscess [13]

A fluctuant mass may indicate a breast abscess.

  • Definition: subareolar periductal chronic inflammatory condition defined by dilated mammary ducts which are eventually clogged [17]
  • Epidemiology
  • Etiology: inspissated luminal secretion stasis leading to periductal inflammation and fibrous obliteration
  • Clinical features
  • Diagnostics
  • Treatment
    • Usually not necessary (most cases resolve spontaneously)
    • Antibiotic therapy if infected
    • Surgical excision for persistent lesions

Mammary duct ectasia is the most common cause of greenish nipple discharge.


Phyllodes tumor [22]

Intraductal papilloma

  • Definition: solitary or multiple benign lesions that arise from the epithelium of the lactiferous breast ducts [23]
  • Epidemiology: peak incidence: 40–50 years
    • Multiple lesions: ∼ 41 years
    • Solitary lesions: ∼ 48 years
  • Etiology: unknown
  • Clinical features [24]
    • Solitary lesions (also known as central papilloma)
    • Multiple lesions (also known as peripheral papilloma)
      • Usually asymptomatic but may cause nipple discharge in rare cases
      • Peripheral lesions
      • Smaller compared to solitary lesions
  • Diagnostics
  • Treatment: surgical excision of the affected duct
  • Prognosis
    • Generally excellent; for most lesions, there is no risk of malignant transformation
    • Lesions with atypical hyperplasia are associated with an increased risk of breast cancer

Intraductal papilloma is the most common cause of bloody nipple discharge.

Lobular carcinoma in situ (LCIS) [26]

  • Characteristics
    • Microcalcifications or production of a mass are rare (usually incidental biopsy finding).
    • Lower risk of subsequent invasive carcinoma (equal predisposition in both breasts) compared to DCIS
  • Localization: multifocal [27]
  • Pathology
    • Decreased E-cadherin expression
    • Lobules filled with monomorphic cells
    • Intact basal membrane
    • Diffuse growth pattern


Types and pathophysiology [29][30]

Physiological gynecomastia

Pathological gynecomastia

Some Hormones Cause Fulminant Kleavage: Spironolactone, Hormones, Cimetidine, Finasteride, Ketoconazole cause gynecomastia.

Idiopathic gynecomastia

  • Up to 25% of patients

Clinical features

Diagnostics [38]

Differential diagnoses

Treatment [39]


Clinical features

  • Firm, nontender mass, typically located in the sub-areolar region
  • Pain suggests secondary infection.

Diagnostics [40]

Primarily a clinical diagnosis

  • Fine needle aspiration: milky substance (diagnostic and therapeutic)
  • Ultrasound
    • Complex mass
    • Findings depend on the fat and water content of the cyst
  • Mammography (rarely indicated): Galactoceles may appear as an indeterminate mass or a mass with the classic fat-fluid level.

Differential diagnosis

Differential diagnosis of galactocele
Content Ultrasound Mammography
  • Fat content very high
Cystic mass with fat-fluid level
  • Fresh milk, and variable proportions of fat and water
  • Fat echogenicity that is higher than fluid
  • Fat-fluid level on mediolateral view
  • A mix of hypoechogenic and hyperechogenic areas
  • Circumscribed mass with characteristic heterogeneous density due to the presence of fat radiolucencies


  • Usually not necessary (most cases resolve spontaneously)
  • Repeated needle aspiration or surgical excision for symptomatic cysts


  1. Sloane E. Biology of Women. Delmar ; 2012
  2. Benign Breast Disease in Women.
  3. Zendehdel M, Niakan B, Keshtkar A, Rafiei E, Salamat F. Subtypes of Benign Breast Disease as a Risk Factor for Breast Cancer: A Systematic Review and Meta-Analysis Protocol.. Iranian journal of medical sciences. 2018; 43 (1): p.1-8.
  4. Visscher DW, Nassar A, Degnim AC, et al. Sclerosing adenosis and risk of breast cancer.. Breast Cancer Res Treat. 2014; 144 (1): p.205-12. doi: 10.1007/s10549-014-2862-5 . | Open in Read by QxMD
  5. Guray M, Sahin AA. Benign breast diseases: classification, diagnosis, and management. Oncologist. 2006; 11 (5): p.435-449. doi: 10.1634/theoncologist.11-5-435 . | Open in Read by QxMD
  6. Fibrosis and Simple Cysts in the Breast. Updated: April 21, 2016. Accessed: March 9, 2017.
  7. Tan PH, Lai LM, Carrington EV, et al. Fat necrosis of the breast—A review. The Breast. 2005; 15 (3): p.313-318. doi: 10.1016/j.breast.2005.07.003 . | Open in Read by QxMD
  8. Upadhyaya VS, Uppoor R, Shetty L. Mammographic and sonographic features of fat necrosis of the breast. Indian J Radiol Imaging. 2013; 23 (4): p.366-372. doi: 10.4103/0971-3026.125619 . | Open in Read by QxMD
  9. Kerridge WD, Kryvenko ON, Thompson A, Shah BA. Fat necrosis of the breast: a pictorial review of the mammographic, ultrasound, CT, and MRI findings with histopathologic correlation. Radiol Res Pract. 2015; 2015 : p.1-8. doi: 10.1155/2015/613139 . | Open in Read by QxMD
  10. Pilnik S. Common Breast Lesions: A Photographic Guide to Diagnosis and Treatment. Cambridge University Press ; 2003
  11. Cerrato F, Labow BI. Diagnosis and management of fibroadenomas in the adolescent breast. Semin Plast Surg. 2013; 27 (1): p.23-25. doi: 10.1055/s-0033-1343992 . | Open in Read by QxMD
  12. Sperber F. Diagnosis and Treatment of Breast Fibroadenomas by Ultrasound-Guided Vacuum-Assisted Biopsy. Arch Surg. 2003; 138 (7): p.796. doi: 10.1001/archsurg.138.7.796 . | Open in Read by QxMD
  13. Mishra SP, Tiwary SK, Mishra M, Khanna AK. Phyllodes tumor of breast: a review article. ISRN Surg. 2013 : p.361469. doi: 10.1155/2013/361469 . | Open in Read by QxMD
  14. Intraductal Papillomas. Updated: April 21, 2016. Accessed: February 18, 2017.
  15. Sabel MS. Overview of Benign Breast Disease. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. updated: July 5, 2017. Accessed: March 6, 2018.
  16. Ghosh AK. Mayo Clinic Internal Medicine Board Review. Oxford University Press ; 2010
  17. Giuliano AE, Edge SB, Hortobagyi GN. Eighth Edition of the AJCC Cancer Staging Manual: Breast Cancer. Ann Surg Oncol. 2018; 25 (7): p.1783-1785. doi: 10.1245/s10434-018-6486-6 . | Open in Read by QxMD
  18. Carniello JS, Giri D, De Brot M, Andrade V, King T. Multifocality and Bilaterality of Lobular Carcinoma In Situ in Women with Synchronous Breast Malignancies. Am J Clin Pathol. 2016; 146 (suppl_1). doi: 10.1093/ajcp/aqw159.085 . | Open in Read by QxMD
  19. Mastitis. Updated: June 12, 2015. Accessed: March 9, 2017.
  20. Dixon JM. Lactational Mastitis. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. updated: March 15, 2016. Accessed: March 9, 2017.
  21. Spencer JP. Management of mastitis in breastfeeding women. Am Fam Physician. 2008; 78 (6): p.727-731.
  22. Lam E, Chan T, Wiseman SM. Breast abscess: evidence based management recommendations.. Expert Rev Anti Infect Ther. 2014; 12 (7): p.753-62. doi: 10.1586/14787210.2014.913982 . | Open in Read by QxMD
  23. Braunstein GD, Anawalt BD. Epidemiology, Pathophysiology, and Causes of Gynecomastia. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. updated: February 10, 2017. Accessed: March 7, 2018.
  24. Kulkarni D, Dixon JM. Congenital Abnormalities of the Breast. Women's Health. 2012; 8 (1): p.75-88. doi: 10.2217/whe.11.84 . | Open in Read by QxMD
  25. Dickson G. Gynecomastia. Am Fam Physician. 2012; 85 (7): p.716-722.
  26. Johnson RE, Murad MH. Gynecomastia: pathophysiology, evaluation, and management. Mayo Clin Proc. 2009; 84 (11): p.1010-1015. doi: 10.1016/S0025-6196(11)60671-X . | Open in Read by QxMD
  27. Bland KI, Copeland EM, Klimberg VS. The Breast. Elsevier Health Sciences ; 2009
  28. Neonatal Gynaecomastia. Updated: January 1, 2018. Accessed: March 6, 2018.
  29. Lazala C, Saenger P. Pubertal gynecomastia. J Pediatr Endocrinol Metab. 2002; 15 (5): p.553-60.
  30. Sanyal T, Dutta D, Shivprasad K, Ghosh S, Mukhopadhyay S, Chowdhury S. Gynaecomastia as the initial presentation of thyrotoxicosis.. Indian journal of endocrinology and metabolism. 2012; 16 (Suppl 2): p.S352-3. doi: 10.4103/2230-8210.104089 . | Open in Read by QxMD
  31. Dickson G. Gynecomastia.. Am Fam Physician. 2012; 85 (7): p.716-22.
  32. Thirumavalavan N, Wilken NA, Ramasamy R. Hypogonadism and renal failure: An update.. Indian journal of urology : IJU : journal of the Urological Society of India. undefined; 31 (2): p.89-93. doi: 10.4103/0970-1591.154297 . | Open in Read by QxMD
  33. Drug-Induced Gynecomastia. Updated: January 1, 2013. Accessed: March 7, 2018.
  34. Braunstein GD. Aromatase and gynecomastia.. Endocr Relat Cancer. 1999; 6 (2): p.315-24.
  35. Mammography Review (E-Book).
  36. Braunstein GD, Anawalt BD. Management of Gynecomastia. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. updated: February 10, 2017. Accessed: March 7, 2018.
  37. Borsuk D, Caouette-Laberge L. Congenital Anomalies of the Breast. Seminars in Plastic Surgery. 2013; 27 (01): p.036-041. doi: 10.1055/s-0033-1343995 . | Open in Read by QxMD
  38. Galactocele. Updated: January 1, 2018. Accessed: May 8, 2019.
  39. Arber DA. Modern surgical pathology. Elsevier ; 2009
  40. Ferris-James DM et al.. Imaging Approaches to Diagnosis and Management of Common Ductal Abnormalities. RadioGraphics. 2012; 32 (4): p.1009-1030. doi: 10.1148/rg.324115150 . | Open in Read by QxMD
  41. Non-cancerous Breast Conditions. Updated: February 18, 2017. Accessed: February 18, 2017.
  42. Fibrocystic breast disease. Updated: April 11, 2014. Accessed: March 9, 2017.