Which modality yields a better breast tissue sample, FNA or core biopsy?

• A. Fine-needle aspiration (FNA)
• B. Core biopsy
• C. Ultrasound-guided FNA
• D. MRI-guided biopsy

Answer: (B)

The main idea is tissue architecture matters for a reliable breast diagnosis. A core biopsy retrieves a small cylinder of tissue, preserving the arrangement of ducts, lobules, and surrounding stroma. That allows the pathologist to evaluate invasiveness, differentiate benign from malignant processes, assess tumor grade, and perform essential tests such as receptor status (ER, PR, HER2) and other stains. In contrast, fine-needle aspiration collects only individual cells or small cell clusters, so there’s no preserved tissue structure. This cytology-only sample can be nondiagnostic or misleading because it lacks architectural context, making it harder to distinguish certain cancers from benign conditions and to assess invasion accurately. Image guidance doesn’t change this fundamental difference: ultrasound-guided sampling can be a core biopsy or an FNA, but the “better sample” in terms of diagnostic completeness is a core biopsy, which is why it’s the preferred modality for breast tissue diagnosis.