Regarding cystic disease of breast which one is true -
• Occur most commonly in the last decade of reproductive life as a result of a non-integrated involution of stroma and epithelium.
Clinical Features
• Often multiple, may be bilateral and can mimic malignancy.
• Typically present suddenly and cause great alarm; prompt diagnosis and drainage provides immediate relief.
Diagnosis
• Diagnosis can be conﬁrmed by aspiration and/or ultrasound.
Treatment
• Aspiration for Solitary cyst: If they resolve completely, and if the ﬂ uid is not blood-stained, no further treatment is required (30% will recur and require reaspiration) 
• Core biopsy or local excision: If there is a residual lump or if the ﬂ uid is blood-stained, for histological diagnosis (exclude cystadenocarcinoma, which is more common in elderly women)
Common in 25 years of age
Excision is the treatment
may turn into malignant
Aspiration is the treatment
Aspiration is the treatment