A biopsy is a procedure in which a sample of tissue is removed from the body for examination. A diagnosis is made when cells are examined through a microscope. There are several ways biopsy samples can be obtained. A punch biopsy is used for obtaining full-thickness samples of the skin. A special instrument, called a punch, is used to create a small hole, or punch, in the skin. This punch works much like a cookie-cutter to remove the entire core of tissue: epidermis, dermis, and fat. A punch biopsy will require sutures to close but leaves minimal scarring. Another type of skin biopsy is a shave biopsy. During this procedure a very thin layer of skin is shaved with a scalpel and is removed for analysis. This is the least invasive type of biopsy and seldom requires sutures. Endoscopic biopsy is performed during endoscopy. Endoscopy is a type of procedure that allows the physician to view the body internally without having to perform an operation. During endoscopy, a tube with a lighted camera is inserted inside the body and can be moved around to obtain different views of organs and tissue. Forceps and brushes that remove tissue samples can also be guided through the tube to obtain a specimen. Bone marrow biopsy uses a long needle to remove cells from the bone marrow. Following administration of a local anesthetic, a large core needle is inserted into the bone. In adults, the sample is usually taken from the back of the hip bone. When enough bone marrow has been obtained, the needle is removed.