Pharyngeal tonsil

The pharyngeal tonsil lies deep to the respiratory mucosa of the nasopharynx and is covered predominantly by pseudostratified ciliated columnar epithelium (respiratory epithelium).

Histologically, the pharyngeal tonsil consists of diffuse lymphoid tissue and lymphoid follicles with germinal centres embedded within the mucosa and submucosa of the nasopharynx. Numerous mucous glands are present in the surrounding submucosa of pharynx.

Adenoid hypertrophy in children

In children, the pharyngeal tonsil is relatively large and physiologically active, usually reaching maximum size during early childhood before gradually regressing after puberty. Pathological enlargement is referred to as adenoid hypertrophy.

Anatomical relations and clinical correlates

• Clinically, enlargement of the pharyngeal tonsil may obstruct the nasopharyngeal airway, causing nasal obstruction, mouth breathing, snoring, and hypo-nasal speech.

• Anatomically, the pharyngeal tonsil is closely related to the openings of the pharyngotympanic (auditory) tubes. Its enlargement may therefore impair drainage or ventilation of the middle ear due to auditory tube obstruction, contributing to recurrent otitis media.

• Inflammation of the pharyngeal tonsil is termed adenoiditis, and severe enlargement may require surgical removal by adenoidectomy.