Breast hypertrophy

Breast hypertrophy is a rare condition that is characterized by abnormal breast enlargement due to excessive tissue growth. Although usually idiopathic, hormonal etiologies include aromatase excess syndrome, hyperprolactinemia, and increased sensitivity to estrogen and progesterone. Clinical features include disproportionately large breasts, mastalgia, inframammary intertrigo, trapezius hypertrophy, and neck, shoulder, and upper back pain. Breast hypertrophy is a clinical diagnosis; laboratory studies and imaging may be indicated to evaluate for an underlying etiology or to rule out other diagnoses. Surgical breast reduction (reduction mammoplasty) is the mainstay of treatment for symptomatic breast hypertrophy. Conservative measures (e.g., proper breast support, upper body physiotherapy) and pharmacotherapy are alternatives when surgery is not feasible.

• Breast hypertrophy (also termed macromastia): excessive proliferation of breast connective tissue, glandular hypertrophy, and/or fatty tissue, resulting in abnormal breast enlargement ^[1]
• Juvenile breast hypertrophy: the rapid enlargement of one or both breasts that usually begins around menarche ^[2]
• Gigantomastia: extreme breast hypertrophy ^[1][2]

• Typically idiopathic; other causes include:
  • Hypersensitivity of estrogen, progesterone, or growth factor receptors
  • Excess hormonal production (e.g., hyperprolactinemia)
  • Aromatase excess syndrome
• Risk factors
  • Immune disorders (e.g., myasthenia gravis, chronic arthritis, Hashimoto thyroiditis) ^[3]
  • Endocrine disorders (e.g., hypercalcemia due to excessive PTHrp)
  • Medications (D-penicillamine, bucillamine, cyclosporine)
  • Severe obesity (BMI > 40)

• Enlarged breasts (symmetrical or asymmetrical)
• Mastalgia
• Pain affecting the neck, shoulders, and upper back
• Skin infections and erythema in intertriginous areas
• Deep, painful bra strap grooving
• Upper extremity neuropathy
• Trapezius muscle hypertrophy
• Thoracic kyphosis
• Psychosocial effects

Breast hypertrophy is a clinical diagnosis based on features consistent with disproportionately large breasts for the individual's body. ^[4][5]

Clinical assessment

• Obtain a thorough history. ^[2][4]
  • Relevant medical history (e.g., breast masses, and rapid breast growth)
  • Pubertal and physical development (e.g., age of thelarche, BMI)
  • Medication review (see “Etiology” section for details)
  • Family history of breast cancer or other breast conditions
• Perform a clinical breast examination (CBE). ^[2]
  • Assess for masses and asymmetry.
  • Evaluate the inframammary folds for intertrigo or other abnormalities.

Laboratory studies ^[2][6]

• Not routinely indicated
• Estradiol, progesterone, prolactin, FSH, LH, and/or urine HCG may be considered to identify potential causes (e.g., hormonal imbalance, pregnancy) or rule out alternative diagnoses.

Imaging ^[2][6][7]

• Indications: to rule out alternative diagnoses or evaluate a palpable breast mass ^[2][7]
• Modalities: Ultrasound and MRI are preferred over mammography. ^[6]

Surgery ^[2][4]

• Indications: symptomatic breast hypertrophy
• Procedures
  • Reduction mammoplasty: preferred option ^[2]
    • Removal of excessive breast parenchyma, fat, and skin
    • May affect the patient's ability to breastfeed
  • Bilateral total mastectomy with breast reconstruction: alternative option ^[2][6]

Conservative management ^[4][6]

• Indications ^[4]
  • Risk factors for surgical complications
  • Patient preference for conservative therapy
• Measures
  • Use of a proper-fitting, supportive bra
  • Upper body physical therapy
  • Pharmacotherapy (under specialist guidance) ^[6]
    • Antiestrogen therapy (e.g., tamoxifen)
    • Progesterone or progestin therapy (e.g., dydrogesterone, medroxyprogesterone)
    • Bromocriptine
    • Danazol

Consider alternatives to progestin-containing contraception in adolescents. Exogenous progestin-only contraception may initially exacerbate breast hypertrophy, but it is not associated with continued breast tissue growth. ^[8]