adeno

Adeno is a combining form derived from the Greek adēn, meaning gland. In medical and biological terminology, adeno- is used to form terms that relate to glands or glandular tissue, or to structures that resemble glands.

The adeno- combining form appears in a variety of terms. Adenoma refers to a benign tumor arising from glandular tissue. Adenocarcinoma denotes a malignant cancer that originates in glandular cells. Adenitis is the inflammation of a gland, while adenopathy describes disease or enlargement of glands, often used specifically for lymph nodes (lymphadenopathy). The name Adenovirus comes from the viruses being first identified in adenoid tissue; the term reflects the tissue of origin rather than the virus’s function.

Adenoid is a related term that describes a mass of lymphoid tissue located in the pharynx, near the nose and throat, historically described as gland-like; adenoids can become enlarged and may affect breathing or hearing in children. The adjective adenoidal (or adenoidal) is used to describe the shape or character resembling glandular tissue.

Notes on usage: adeno- is a combining form that attaches to roots to indicate gland-related meaning. It is distinct from the root aden-, which appears in other contexts (such as adenosine or other chemical names) but shares the same etymological origin from adēn. In practice, adeno- is primarily encountered in medical terminology and anatomical discourse.