A core needle biopsy is a medical procedure used to obtain a small sample of tissue from a suspicious area, often in the breast or other organs. A hollow needle is inserted into the area to extract a cylindrical piece of tissue, which is then examined under a microscope for signs of disease, such as cancer. This method is less invasive than surgical biopsies and can provide valuable information for diagnosis. The procedure is typically performed using local anesthesia to minimize discomfort. It is guided by imaging techniques like ultrasound or CT scans to ensure accurate targeting of the tissue. Results from a core needle biopsy help doctors determine the best course of treatment.