Synopsis
Recognise simple, complicated and complex cystic breast lesions, use ultrasound and aspiration appropriately, and investigate residual, recurrent or bloody abnormalities rather than assuming all fluid-containing masses are benign.
- Breast cysts arise when terminal duct-lobular units distend with fluid and are common around the perimenopause, but a new lump still requires age-appropriate assessment.
- A simple cyst is anechoic, thin-walled and well circumscribed with posterior enhancement and no solid component; these imaging features support benignity when they explain the palpable target.
- Complicated internal echoes may represent debris or blood, whereas a thick wall, mural nodule, vascular solid component or irregular margin creates a complex lesion needing tissue-directed evaluation.
Investigation priorities
Confirm whether the palpable target is fluid filled and assess wall, contents and any solid component.
Management branches
A 49-year-old has a tender 3 cm lump; ultrasound shows a simple cyst exactly at the palpable site.
- Explain the benign imaging features and offer observation if discomfort is tolerable, because a simple cyst does not need aspiration solely to prove its existence.
- If symptoms justify treatment, aspirate under ultrasound guidance using aseptic technique and document the volume and character of fluid.