A lymph node biopsy is a procedure in which a sample of tissue is removed from one or more lymph nodes in the neck, armpit, groin, chest or abdomen for close examination under a microscope. Such examination may reveal the presence of an infection or disease, and is often used to determine whether cancer has spread from one part of the body to another. The tissue sample may be extracted via a fine needle aspiration biopsy, where a thin needle is employed to collect cells from the designated lymph node. Alternatively, a cylinder-shaped sample of tissue may be collected via a core needle biopsy, where a needle with a special tip is employed. When a larger tissue sample is required, options include an “open” biopsy, where the entire lymph node is removed via surgical extraction, and a lymph node dissection, in which multiple lymph nodes are extracted.