When assessing breast masses, which biopsy method is generally preferred to differentiate in situ from invasive disease?

When assessing breast masses, which biopsy method is generally preferred to differentiate in situ from invasive disease?

• A. Excisional biopsy
• B. Fine-needle aspiration
• C. Core needle biopsy
• D. Vacuum-assisted biopsy

Answer: (C)

Distinguishing in situ from invasive breast cancer relies on seeing cancer cells piercing the basement membrane and invading surrounding stroma, which requires tissue with preserved architecture for accurate assessment. A core needle biopsy provides multiple preserved tissue cores, giving the pathologist enough architecture to evaluate invasion, histologic grade, and receptor status while remaining minimally invasive. This makes it the most reliable initial method to differentiate in situ from invasive disease. Fine-needle aspiration collects mainly cells without architectural context, so it cannot reliably distinguish invasion. Excisional biopsy removes the entire lesion and is more invasive, used when percutaneous sampling is nondiagnostic or when complete removal is planned. Vacuum-assisted biopsy samples more tissue and can be helpful in certain scenarios, but it is not the standard first-line method for determining invasion.

Distinguishing in situ from invasive breast cancer relies on seeing cancer cells piercing the basement membrane and invading surrounding stroma, which requires tissue with preserved architecture for accurate assessment. A core needle biopsy provides multiple preserved tissue cores, giving the pathologist enough architecture to evaluate invasion, histologic grade, and receptor status while remaining minimally invasive. This makes it the most reliable initial method to differentiate in situ from invasive disease.

Fine-needle aspiration collects mainly cells without architectural context, so it cannot reliably distinguish invasion. Excisional biopsy removes the entire lesion and is more invasive, used when percutaneous sampling is nondiagnostic or when complete removal is planned. Vacuum-assisted biopsy samples more tissue and can be helpful in certain scenarios, but it is not the standard first-line method for determining invasion.