A biopsy needle is a medical instrument used to extract tissue samples from the body for diagnostic purposes. It is often employed when doctors suspect the presence of diseases, such as cancer, in organs like the breast, lung, or prostate. The needle can be inserted through the skin or guided by imaging techniques like ultrasound or CT scans to ensure accurate sampling. There are different types of biopsy needles, including fine-needle aspiration needles and core needles. Fine-needle aspiration needles are thinner and used for smaller samples, while core needles are larger and provide more tissue for analysis. The collected samples are then examined under a microscope by a pathologist to determine the presence of disease.