Head and Neck ImagingWaldeyer's ring
(Heinrich Wilhelm Gottfried von Waldeyer,1836 - 1921, German anatomist)
1. Anatomy
Ring of lymphoid tissue, formed by the lingual tonsil, palatine tonsils (also called faucial tonsils), and nasopharyngeal tonsils (also called adenoids). It appears during the first few months after birth, is prominent during childhood, and gradually involves from puberty on. Normal lymphoid tissue of Waldeyer's ring appears as homogeneous soft tissue, sometimes lobulated. Radiological differentiation between normal lymphoid tissue, (inflammatory) hypertrophy and tumour may be difficult. Also, see also adenoids.
2. Pathology
congenital
If no adenoids are seen by the age of 6 months, a problem with the immune system should be suspected.
inflammation
Hypertrophy of the nasopharyngeal tonsil and palatine tonsils is commonly seen in children. Hypertrophy of the adenoids commonly causes dysfunction of the eustachian tube, which on its turn causes serous otitis media. Hypertrophy of the palatine tonsils may cause dysphagia and breathing difficulties; these symptoms are less commonly seen with lingual tonsil hypertrophy. Also, see pharyngitis.
tumour
Waldeyer's ring is a common site for extranodal non Hodgkin lymphoma head and neck manifestation. Primary squamous cell carcinoma head and neck may hide in crypts within lymphoid tissue of Waldeyer's ring; in the case of an unknown primary tumour, sites which should receive special attention include the tongue base, palatine tonsils and nasopharynx (also, see occult primary tumour head and neck).
RH