Which of the following is the most common benign breast tumor in women of reproductive age?

Explanation

## Fibroadenoma: Epidemiology and Classification **Key Point:** Fibroadenoma is the most common benign breast tumor in women aged 15–35 years, accounting for approximately 50% of all benign breast lesions in this age group. ### Characteristics of Fibroadenoma | Feature | Details | |---------|----------| | **Age of presentation** | 15–35 years (reproductive age) | | **Incidence** | Most common benign breast tumor in young women | | **Etiology** | Estrogen-dependent; proliferation of epithelium and stroma | | **Malignant potential** | < 0.1% (extremely low) | | **Growth pattern** | Slow, self-limited; may regress postmenopausally | **High-Yield:** Fibroadenomas are benign, painless, mobile masses that do NOT increase breast cancer risk. They are often discovered incidentally or as a palpable lump by the patient. ### Clinical Presentation - Well-defined, firm, mobile mass ("breast mouse") - No skin changes or nipple discharge - Usually solitary, but 10–25% are multiple (complex fibroadenomas) - No axillary lymphadenopathy ### Imaging and Diagnosis - **Ultrasound:** Hypoechoic, well-circumscribed lesion - **Mammography:** Radiopaque mass with smooth borders - **Core needle biopsy or excision:** Confirms diagnosis (phyllodes must be excluded) **Clinical Pearl:** The term "breast mouse" refers to the high mobility of fibroadenoma within the breast tissue, which helps distinguish it from malignant lesions. ### Management - **Observation:** Safe for young women with typical imaging features - **Excision:** Indicated if rapid growth, diagnostic uncertainty, or patient preference - **Hormone therapy:** Not recommended; does not prevent growth [cite:Robbins 10e Ch 24]