Core needles are specialized medical instruments used to extract a small cylinder of tissue from a specific area of the body. This procedure, known as a core biopsy, helps doctors diagnose various conditions, including cancer, by providing a sample for examination under a microscope. Core needles come in different sizes and designs, allowing for precise sampling from organs like the breast, lung, or prostate. These needles typically have a hollow, cylindrical shape and are often guided by imaging techniques such as ultrasound or CT scans to ensure accurate placement. The procedure is minimally invasive, usually performed on an outpatient basis, and can provide valuable information while minimizing recovery time for patients.