Synopsis
Recognise a milk-retention cyst during or after lactation, distinguish it from abscess and solid tumour on imaging, and use aspiration or biopsy when symptoms, infection or discordance require intervention.
- A galactocele is a milk-retention cyst caused by duct obstruction during pregnancy, breastfeeding or soon after weaning and commonly presents as a painless mobile mass.
- Ultrasound appearances vary with fat, protein and water content; a fat-fluid level is suggestive, while thick contents can create internal echoes that resemble a solid lesion.
- Clinical and imaging assessment must localise the same mass because lactation does not protect against fibroadenoma, abscess or pregnancy-associated breast cancer.
Investigation priorities
Confirm cystic anatomy, assess internal contents and plan a safe route for diagnostic sampling or therapeutic drainage.
Management branches
A breastfeeding patient has a 2 cm mobile lump; ultrasound shows a classic fat-fluid cyst with no vascular solid component.
- Map the mass and assess feeding, weaning changes, pain, fever, skin and nodes so the imaging is correlated with the actual target.
- Explain the milk-retention mechanism and offer observation because the lesion is small, comfortable and radiologically concordant.
A galactocele becomes hot and tender with fever and turbid fluid. After urgent assessment, the breastfeeding adult is stable without sepsis, spreading cellulitis or threatened skin; renal function is preserved, the infant is healthy and term, and there is no beta-lactam allergy or MRSA risk.
Key medicines
Flucloxacillin for an infected lactational galactoceleAfter assessment and drainage, the NHS Highland adult breast-abscess example is flucloxacillin 500 mg orally four times daily for 7–10 days. Apply it to a stable patient without relevant allergy or MRSA risk, then review culture and improvement; this differs from the NHS Dumfries & Galloway 10–14-day mastitis pathway.Use the 500 mg capsules on an empty stomach, one hour before or two hours after meals, with 250 mL water and no immediate lying down. Exclude beta-lactam or product hypersensitivity and previous flucloxacillin-associated jaundice/liver dysfunction. Review hepatic disease and interactions including methotrexate, warfarin/INR, probenecid and voriconazole. CrCl under 10 mL/min needs prescriber consideration of a reduced dose or extended interval. Concurrent paracetamol in severe renal impairment, sepsis or malnutrition requires acidosis-risk review and monitoring. Monitor the healthy term infant for gastrointestinal symptoms, thrush, rash or feeding difficulty; severe maternal illness or an unwell/premature infant needs individual specialist advice.
Lidocaine 10 mg/mL for drainage-site anaesthesiaUse plain Aguettant 1% lidocaine by local intradermal/subcutaneous infiltration, selecting the minimum effective volume. The product gives a usual adult infiltration total of 3–5 mg/kg and a generally recommended 200 mg ceiling, equivalent to 20 mL. Do not aim for the ceiling; adjust the dose to the patient and procedure.An experienced clinician with resuscitation facilities should administer it. Amide-local-anaesthetic/product allergy excludes use; cardiac or liver insufficiency may need up to a half-dose reduction, and renal impairment or frailty can require further individual adjustment. Review conduction disease, seizures, anticoagulants, other local anaesthetics and antiarrhythmic/metabolic interactions. Infected tissue has poorer anaesthetic effect and greater systemic absorption; avoid intravascular injection and monitor for toxicity. Stop and initiate urgent assessment/resuscitation for perioral sensory change, tinnitus, seizures, arrhythmia or collapse. The IVRA 3 mg/kg maximum and adrenaline-mixture rules are not infiltration rules; recommended local doses are compatible with continued breastfeeding.