A 22-year-old woman presents to the breast clinic with a 2 cm firm, mobile, painless lump in the upper outer quadrant of her left breast. She noticed it 6 months ago and reports it has not changed in size. On examination, the lump is well-defined, rubbery, and moves freely with breast tissue. Skin and nipple are normal. Axillary lymph nodes are not palpable. Mammography is not performed due to her age. Ultrasound shows a hypoechoic, well-circumscribed lesion with no internal vascularity. What is the most appropriate management?

Explanation

## Clinical Diagnosis **Key Point:** This presentation is classic for fibroadenoma — a benign breast lesion in a young woman with a firm, mobile, well-circumscribed mass and benign imaging features. ## Imaging Characteristics | Feature | Fibroadenoma | Malignancy | |---------|--------------|------------| | Margins | Well-defined, circumscribed | Irregular, spiculated | | Vascularity | Minimal/absent on Doppler | Increased on Doppler | | Shape | Oval/round | Irregular | | Mobility | High (moves freely) | Fixed | ## Management Algorithm for Benign Breast Lesions ```mermaid flowchart TD A[Young woman with breast mass]:::outcome --> B{Imaging features benign?}:::decision B -->|Yes| C{Diagnostic certainty high?}:::decision C -->|Yes - BI-RADS 2/3| D[Clinical observation + imaging follow-up]:::action C -->|No or patient anxiety| E[Core needle biopsy]:::action B -->|No - suspicious| F[Excision biopsy]:::action D --> G[Reassure patient, 6-monthly US]:::action E --> H{Benign confirmed?}:::decision H -->|Yes| I[Observation or excision per patient choice]:::action H -->|No| F ``` **High-Yield:** In young women with imaging-confirmed benign fibroadenomas (BI-RADS 2–3), observation with serial ultrasound is safe and avoids unnecessary surgery. Excision is offered if: - Patient anxiety or cosmetic concern - Diagnostic uncertainty - Rapid growth (>2 cm/year) - Lesion causing symptoms **Clinical Pearl:** Fibroadenomas are hormone-responsive and may regress spontaneously, especially after menopause. Up to 20% involute over 2–3 years. ## Why Not Immediate Excision? Excision of every benign fibroadenoma would result in unnecessary surgery in a young woman with a benign diagnosis. The BI-RADS 3 (probably benign) ultrasound and classic clinical features allow safe observation. **Key Point:** Excision is reserved for diagnostic uncertainty, rapid growth, or patient preference — not routine for stable, imaging-confirmed benign lesions.