A biopsy (in Greek: bios = life and opsy = look/appearance) is a medical test involving the removal of cells or tissues for examination. The tissue is often examined under a microscope and can also be analyzed chemically (for example, using PCR techniques).

When only a sample of tissue is removed, the procedure is called an incisional biopsy or core biopsy . When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy . When a sample of tissue or fluid is removed with a needle, the procedure is called a needle biopsy or fine-needle aspiration .

See also: pathology, autopsy