Breast fibroadenoma

Disease Description (Causes and Symptoms)

• Definition summary: Fibroadenoma of the breast is a benign mass formed by excessive proliferation of the epithelium and stroma (fibrous tissue) in the terminal duct-lobular unit of the mammary gland. It is known to respond to estrogen and is common in women of reproductive age.
• Typical age/subtypes: Occurs mainly from the late teens to the early 30s. Giant fibroadenomas (>5 cm) and juvenile fibroadenomas that occur in children and adolescents may develop. They may grow rapidly during pregnancy, breastfeeding, or puberty.
• Pathophysiology: Localized proliferation of epithelial and stromal elements in the terminal ducts → formation of a well-circumscribed, rubbery nodule. Because of estrogen sensitivity, the size may change with the menstrual cycle and hormonal changes.
• Main symptoms:
  • Usually a firm, rubbery, well-circumscribed, freely movable lump that can be felt without pain
  • Usually stops growing at 1–3 cm, but may grow to 4–5 cm or larger
  • Usually solitary, but multiple lesions are possible
  • When observed for 1 year, approximately 12–16% may decrease in size or disappear
  • Rarely (0.1–0.3%), cancerous tissue may be present within a fibroadenoma

Treatment Methods (Standard Treatment·Medications·Procedures·Lifestyle Management·Precautions)

• Diagnostic approach:
  • Under 30 years of age: ultrasound (US) first
  • 30 years or older (or when imaging is suspicious): mammography (film/digital) and ultrasound together
  • Tissue diagnosis: confirmation with a core needle biopsy or diagnostic excision (or minimally invasive removal)
• Conservative management (observation):
  • If fibroadenoma is confirmed by imaging and/or biopsy and there are no symptoms, periodic follow-up (e.g., ultrasound after 6 months, then every 6–12 months) may be used for observation
• Removal based on indications:
  • Rapid growth (increase in size over a short period), 2–3 cm or larger (criteria vary according to the institution and clinical guidelines), symptoms (pain or cosmetic concerns), uncertain or atypical findings on imaging or biopsy, or when the patient wants removal because of anxiety
• Removal methods:
  • Surgical excision (excision of the mass under local or general anesthesia in a breast surgery department)
  • Vacuum-assisted excision: may be used minimally invasively for small nodules
  • Nonsurgical methods such as cryoablation are performed at some centers
• Precautions and complications:
  • Possible postoperative scarring, infection, bleeding, and recurrence of the mass
  • Malignant transformation of a fibroadenoma itself is very rare (0.1–0.3%), but active tissue biopsy is recommended for a newly occurring lump or atypical findings in people aged 40 or older
  • During pregnancy and breastfeeding, observation is preferred whenever possible, but biopsy and treatment should be considered if there is a rapid increase in size or suspicious findings
• Self-care:
  • Perform regular breast self-examinations and follow the scheduled follow-up examination plan (ultrasound/mammography)
  • If taking hormonal therapy (oral contraceptives or HRT), consult the treating physician

Checkpoints Before an Outpatient Visit (Including Items to Prepare and Example Questions)

• Items to prepare (bringing these can facilitate the consultation):
  • A list of currently used medications and supplements (including hormonal medications)
  • Family history (including breast cancer) and personal medical history (records of breast surgery or biopsy)
  • Results and reports from previous breast imaging (mammography/ultrasound)
  • When symptoms began, changes in size (photos or measurement records are useful), cyclicity (relationship to menstruation), and whether pain or nipple discharge is present
  • Possibility of pregnancy and whether you are breastfeeding
• Key information to tell the doctor first during the outpatient visit:
  • The rate of change in the size of the lump (changes over the past several months)
  • Breast skin changes (dimpling or redness), whether the lump is fixed, and whether there is lymph node enlargement
  • Previous biopsy results or pathological findings

Examples of General Questions to Ask the Doctor

• "Is this lump definitely a benign fibroadenoma? Do I need a biopsy?"
• "Is this something that can be observed? How often should I have follow-up examinations?"
• "If I have surgery, what kind of scar will remain, and how high is the risk of complications?"
• "Among the surgical or removal methods (such as vacuum-assisted removal), which method do you recommend?"
• "How likely is recurrence after treatment, and what is the prognosis?"

Examples of Condition-Specific Questions (1–2)

• "Can this lump be removed using a nonsurgical method (e.g., vacuum-assisted excision or cryoablation)? What are the eligibility criteria, such as size?"
• "I am pregnant (or breastfeeding). Is this a situation in which I need a biopsy or removal immediately, or can it be postponed until after delivery?"

Additional note: When a lump is newly discovered in someone aged 40 or older or the imaging findings are abnormal, more active tissue biopsy (or immediate excision) is generally recommended. Discuss diagnostic and treatment decisions with the treating breast surgeon, taking into account age, imaging findings, biopsy results, and patient preferences.