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). A medical test is any kind of diagnostic procedure performed for health reasons. ... Cells in culture, stained for keratin (red) and DNA (green) The cell is the structural and functional unit of all living organisms, sometimes called the building blocks of life. ... Biological tissue is a group of cells that perform a similar function. ... 1852 microscope Compound microscope made by John Cuff in 1750 A microscope (Greek: micron = small and scopos = aim) is an instrument for viewing objects that are too small to be seen by the naked or unaided eye. ... Wikipedia does not yet have an article with this exact name. ...

Biopsy specimens are often taken from part of a lesion when the cause of a disease is uncertain or its extent or exact character is in doubt. Vasculitis, for instance, is usually diagnosed on biopsy. Additionally, pathologic examination of a small biopsy can help differentiate between different types of cancer and determine whether a lesion is benign or malignant. In contrast to a biopsy that merely samples a lesion, a larger excisional specimen called a resection may come to a pathologist, typically from a surgeon attempting to eradicate a known lesion from a patient. For example, a pathologist would examine a mastectomy specimen, even if a previous nonexcisional breast biopsy had already established the diagnosis of breast cancer. Examination of the full mastectomy specimen would confirm the exact nature of the cancer (subclassification of tumor and histologic "grading") and reveal the extent of its spread (pathologic "staging"). In medicine, vasculitis (plural: vasculitides) is a group of diseases featuring inflammation of the wall of blood vessels. ... In medicine, mastectomy is the medical term for the surgical removal of one or both breasts, partially or completely. ... In the context of pathology, staging refers to the evaluation of a disease in terms of its progression in the body, or stage. ...

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 aspiration biopsy. Needle aspiration biopsy is a procedure performed to diagnose and treat certain kind of illnesses. ...

See also: pathology, autopsy Pathology (in ancient Greek pathos = feeling, pain, suffering and logos = discourse or treatise, i. ... An autopsy (also known as a post-mortem examination or necropsy) is a medical investigation of a corpse to determine the cause of death. ...