Inanatomy, thepharyngeal tonsil, also known as thenasopharyngeal tonsil oradenoid, is thesuperior-most of thetonsils. It is a mass oflymphoid tissue located behind thenasal cavity, in the roof and the posterior wall of thenasopharynx,[1] where thenose blends into thethroat. Inchildren, it normally forms a soft mound in the roof and back wall of the nasopharynx, just above and behind theuvula.
The termadenoid is also used to representadenoid hypertrophy, the abnormal growth of the pharyngeal tonsils.[2]
Adenoids develop from a subepithelial infiltration oflymphocytes after the 16th week of embryonic life. After birth, enlargement begins and continues until ages 5 to 7 years.
Part of the immune system, adenoids trap and recognize pathogens such as bacteria and viruses. In response, the adenoid producesT cells andB cells to combat infection, contributing to the synthesis of IgAimmunoglobulins, assisting in the body's immunologic memory.[4]
An enlarged adenoid, oradenoid hypertrophy, can become nearly the size of aping pong ball and completely block airflow through the nasal passages. Even if the enlarged adenoid is not substantial enough to physically block the back of the nose, it can obstruct airflow enough so that breathing through the nose requires an uncomfortable amount of work, and inhalation occurs instead through an open mouth. The enlarged adenoid would also obstruct the nasal airway enough to affect the voice without actually stopping nasal airflow altogether.
Symptomatic enlargement between 18 and 24 months of age is not uncommon, meaning thatsnoring, nasal airway obstruction and obstructed breathing may occur during sleep. However, this may be reasonably expected to decline when children reach school age, and progressive shrinkage may be expected thereafter.[citation needed]
Enlargement of the adenoid, especially in children, causes an atypical appearance of the face, often referred to asadenoid facies.[5] Features of adenoid facies includemouth breathing, an elongated face, prominent incisors,hypoplasticmaxilla, short upper lip, elevated nostrils, and a high arched palate.[6]
Surgical removal of the adenoid is a procedure calledadenoidectomy. Adenoid infection may cause symptoms such as excessivemucus production, which can be treated by its removal. Studies have shown that adenoid regrowth occurs in as many as 19% of the cases after removal.[7] Carried out through the mouth under ageneral anaesthetic (or less commonly atopical), adenoidectomy involves the adenoid beingcuretted,cauterized,lasered, or otherwiseablated. The adenoid is often removed along with thepalatine tonsils.[8]
^Lesinskas, Eugenijus; Drigotas, Martynas (2009-04-01). "The incidence of adenoidal regrowth after adenoidectomy and its effect on persistent nasal symptoms".European Archives of Oto-Rhino-Laryngology.266 (4):469–473.doi:10.1007/s00405-008-0892-5.ISSN1434-4726.PMID19093130.S2CID31941117.
^"Adenoids". MedlinePlus, US National Library of Medicine. 13 September 2022. Retrieved23 July 2023.
