Which procedure involves the removal of a tissue section for medical testing?

A biopsy involves the removal of a tissue section for medical testing, which is crucial for diagnosing diseases, especially cancers. During this procedure, a small sample of tissue is extracted from a specific area of concern within the body and examined microscopically. This allows medical professionals to assess the nature of the tissue, identify abnormalities, and determine the presence of conditions such as tumors.

In contrast, a pellicle refers to a thin skin or film, which does not pertain to the sampling of tissue for diagnostic purposes. Cyst formation involves the development of a sac-like pocket of tissue that may contain fluid, gas, or other substances, but it doesn't specify any process of removal or analysis. Chemotherapy, while a treatment method for cancer involving powerful drugs to kill or slow the growth of cancer cells, is not focused on the removal of tissue for testing but rather the treatment of the condition diagnosed potentially through a biopsy.