Biopsy (definition of)

A biopsy is a diagnostic procedure during which cells or a tissue sample is removed from the body and subject to chemical analysis and visual examination in order to determine the presence of disease. For many types of cancer, including mesothelioma, this is one method by which a diagnosis is confirmed.

The process actually dates back to the Middle Ages, when the Arab physician Abu al-Qasim (ca. 936-1013), practicing in what is now the Andalusia region of Spain, used a needle in order to puncture a goiter and observe the material that was released.

When it comes to cancer, an "excisional" biopsy may be performed, in which an entire lump or area showing signs of malignancy is removed, or a "needle aspiration" biopsy, when only a minimal sample is needed. The excisional biopsy is an involved process that usually requires surgery in a sterile environment and an overnight hospital stay. Needle aspiration is relatively minor and minimally invasive.