Galactocele

Galactoceles are milk retention cysts that primarily occur during or shortly after lactation. The typical presentation includes a firm nontender or mildly tender breast mass. Ultrasound is the preferred modality to evaluate palpable breast masses in lactating patients. Galactoceles have a variable appearance on ultrasound, ranging from a simple anechoic cyst to a mass with internal echoes. Mammography may be required to evaluate inconclusive ultrasound findings; detection of an oil-fluid cyst is pathognomonic for galactoceles. Asymptomatic galactoceles typically regress and can be managed expectantly. Symptomatic galactoceles often require fine needle aspiration and drainage catheter placement, and in the case of infection, antibiotic therapy. See also “Breast abscess.”

• Frequently occurs during or after lactation ^[1]
• Most common benign breast lesion in lactating women who have recently stopped breast feeding ^[1][2]

Epidemiological data refers to the US, unless otherwise specified.

Obstruction of lactiferous duct → distention of the duct due to collection of milk and epithelial cells → cyst formation

• Firm, nontender mass, typically located in the subareolar region
• Size may fluctuate (e.g., decrease in size after breastfeeding) ^[3]
• Severe pain and systemic signs suggest secondary infection.

The diagnosis is primarily clinical and based on the patient's history and clinical presentation. A palpable breast mass always requires further evaluation. ^[2][4][5]

Breast imaging

Breast ultrasound

• Indications: first-line imaging modality for evaluation of a palpable breast mass or focal pain in pregnant and lactating women ^[1][5]
• Findings are variable and include: ^[1][6]
  • Anechoic simple breast cyst with posterior acoustic enhancement ^[1]
  • Mass with variable echogenicity and internal echoes (but no vascular flow) ^[6]
  • Fat-fluid level ^[2]
  • Irregular borders and wall thickening ^[1][6]

Mammography

• Indications ^[1][5]
  • Second-line imaging modality in lactating (or pregnant) women with a palpable breast mass and a negative or equivocal ultrasound
  • As an adjunct to ultrasound to further evaluate concerning features
• Findings ^[1]
  • Well-defined mass
  • Depending on the fat and fluid content within the mass, the following features may be seen: ^[2]
    • Fat-fluid level
    • Uniformly radiolucent mass
    • Heterogeneous density

Imaging-guided fine needle aspiration ^[1]

• Indications ^[2][6]
  • Diagnostic uncertainty or suspicious findings on imaging
  • Possible infection
  • Bothersome symptoms (e.g., pain, swelling)
• Findings: milky aspirate ^[1]
• Complications: milk fistula ^[2][5][7]

Asymptomatic galactoceles

• Surveillance with clinical examination and/or imaging ^[8]
• Treatment is usually unnecessary (most galactoceles resolve spontaneously). ^[6][9]

Symptomatic galactoceles ^[3][9]

• Needle aspiration: for symptomatic relief (and additional diagnostic confirmation)
• Drainage catheter placement: often recommended to facilitate fluid removal
• Empiric antibiotic therapy for breast infections: indicated for infected galactoceles ^[2][3][9]

Repeated needle aspiration increases the risk of infection but is typically required before a galactocele fully resolves. The placement of a catheter to allow continued drainage facilitates resolution. ^[3]

• Usually good
• No increased risk of subsequent breast cancer