Lactational Galactocele

Lactational galactocele is a milk filled cyst in the breast caused by obstruction of a milk duct, which develops during lactation or soon after weaning. It is a common benign breast mass in breastfeeding women, appearing as a smooth, mobile, painless lump. It matters because it is easily mistaken for a tumour or abscess, and treatment is simple aspiration or observation.

• Risk factors: blocked milk ducts, abrupt weaning, previous galactocele, oral contraceptive use, breastfeeding for more than 6 months, nipple trauma.
• The cyst contains milk that may thicken to a cheesy paste.
• Most resolve within weeks to months after weaning.

Women have a smooth, round, mobile, usually painless lump, 1 to 5 cm, in one breast, which is firm or cystic and does not change with feeds. The overlying skin is normal, and there is no fever unless infection develops.

• Cyst near the areola, soft or firm, with clear borders.
• Milky fluid on aspiration.
• Differential diagnosis: fibroadenoma, lactating adenoma, breast abscess, simple cyst, blocked milk duct, lipoma, fat necrosis, intraductal papilloma, phyllodes tumour, breast cancer.
• Complications: infection and abscess, recurrence, persistent lump, pain, rarely calcification.

The approach is imaging and aspiration, with biopsy for atypical features.

• Examination of the breast and axilla; transillumination is unreliable.
• Ultrasound: well defined cystic mass with fluid and fat levels, or complex echogenic mass with a thin wall; mammography shows a fat fluid level or a rounded mass with halo in women aged 40 years or above.
• Needle aspiration with a 21 gauge needle yields thick milky fluid (confirms diagnosis); cytology if the fluid is bloody or atypical.
• Core biopsy if the mass is solid, complex or does not resolve after aspiration.

The principle is reassurance and observation for small cysts, aspiration for symptomatic ones, and antibiotics if infected.

• Supportive: reassurance that the lump is benign; continue breastfeeding; warm compress before feeds; gentle massage toward the nipple; supportive bra; observation for 4 to 6 weeks for small asymptomatic cysts.
• Pharmacological: lignocaine 1 percent infiltration, 2 to 5 mL (maximum 3 mg/kg, not above 200 mg), for aspiration; paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours); ibuprofen 400 mg oral 8-hourly with food for 3 to 5 days; if infected: flucloxacillin 500 mg oral 6-hourly for 10 days, or cefalexin 500 mg oral 6-hourly for 10 days, or clindamycin 300 mg oral 6-hourly for 10 days in penicillin allergy.
• Procedures: ultrasound guided needle aspiration for symptomatic or large cysts (milky fluid, may refill and need repeat); core biopsy of a persistent or complex mass; surgical excision of a recurrent cyst or one that remains after 3 aspirations, or of a solid component with atypical cells.
• Red flags: hard fixed mass, bloody aspirate, solid component on ultrasound, skin changes, nipple retraction, fever with redness (infected galactocele), axillary nodes that are hard.
• Follow-up: review at 4 to 6 weeks and after weaning; repeat ultrasound at 3 months if the lump persists; breast examination at 6 weeks after weaning; biopsy for any lump that persists beyond 3 months or enlarges.