Describe the epidemiology.
Simple breast cysts are a common cause of breast lesions identified on examination or imaging.
Peak incidence (of simple cysts): 35–50 years of age; most common in premenopausal women
List clinical features.
Maybe asymptomatic (detected incidentally)
Single or multiple breast masses
May be tender
Variable size (microcysts, gross cysts, clusters) and texture (smooth, soft, firm)
Cystic and solid breast masses cannot reliably be distinguished on physical examination alone.
Describe the overall management.
Follow age-appropriate breast imaging for a palpable breast mass.
Use targeted ultrasound to evaluate any masses identified on mammography. 
Tailor further management based on imaging findings.
Simple breast cyst: no further diagnostic evaluation 
Complex breast cyst: ultrasound-guided core needle biopsy or excisional biopsy to rule out concomitant malignancy
Complex breast cyst: surveillance, therapeutic aspiration, or biopsy depending on clinical concern for malignancy
Ultrasound is the preferred modality for differentiating between cystic and solid breast masses.
Biopsy is recommended for all breast cysts with suspicious features (e.g., doppler flow, thick septations or walls, solid components).
Cytological evaluation is recommended if bloody fluid is obtained on therapeutic or diagnostic aspiration.