Adenoids

In 1724, Santorini first described the nasopharyngeal lymphoid aggregate as Luschka’s tonsil. The term ‘adenoids’ was later coined by Wilhelm Meyer in 1870. The adenoid forms a part of Waldeyer’s ring, a collection of lymphoid tissue situated at the entrance of the upper respiratory tract. During early childhood, the adenoid is the initial site of immunological contact for inhaled antigens. Historically, the adenoids has been linked to upper airway obstruction, sepsis, and more recently, the persistence of otitis media with effusion.

The primary function of the lymphoid tissue in Waldeyer’s ring is antibody production. The adenoid generates B-cells, which differentiate into IgG and IgA plasma cells. Early exposure to antigens through the mouth and nose is crucial for the development of naturally acquired immunity in young children. The adenoid plays a significant role in the development of immunological memory during early childhood. Consequently, the removal of the adenoid at a young age may be immunologically undesirable.

ANATOMY AND PHYSIOLOGY

The nasopharyngeal tonsil, commonly referred to as the “adenoids,” is located where the roof and posterior wall of the nasopharynx meet. It consists of vertical ridges of lymphoid tissue separated by deep clefts and is covered by three types of epithelium: ciliated pseudostratified columnar, stratified squamous, and transitional. Unlike the palatine tonsils, the adenoids lack crypts and a capsule. Adenoid tissue is present at birth and undergoes physiological enlargement until about six years of age, after which it begins to atrophy during puberty. The adenoids are relatively largest in proportion to the nasopharynx volume around the age of seven. Regression of adenoid tissue occurs rapidly after fifteen years of age in most children and almost completely disappears by the age of twenty. Clinical symptoms related to the adenoids are more common in younger children due to the smaller volume of the nasopharynx and the higher frequency of upper respiratory tract infections.

Blood supply. Adenoids receive their blood supply from:

1. Ascending palatine branch of facial.
2. Ascending pharyngeal branch of external carotid.
3. Pharyngeal branch of the third part of maxillary artery.
4. Ascending cervical branch of inferior thyroid artery of thyrocervical trunk.

Venous drainage is through the internal jugular and facial veins.

Lymphatics from the adenoid drain into upper jugular nodes directly or indirectly via retropharyngeal and para-pharyngeal nodes.

Nerve supply is through CN IX and X. They carry sensation. Referred pain to the ear due to adenoiditis is also mediated through them.

 AETIOLOGY

• Recurrent attacks of rhinitis
• Sinusitis
• Chronic tonsillitis.
• Allergy of the upper respiratory tract

CLINICAL FEATURES

Symptoms and signs of adenoid enlargement are influenced not only by the absolute size of the adenoid mass but also by the available space in the nasopharynx. Enlarged and infected adenoids can cause nasal, aural, or general symptoms.

Nasal Symptoms

1. Nasal Obstruction: The most common symptom, leading to mouth breathing. Nasal obstruction interferes with feeding or suckling in children, as respiration and feeding cannot occur simultaneously, causing failure to thrive.
2. Nasal Discharge: Partly due to choanal obstruction, preventing normal nasal secretions from draining into the nasopharynx, and partly due to associated chronic rhinitis. This often results in a wet, bubbly nose.
3. Sinusitis: Chronic maxillary sinusitis is commonly associated with adenoids due to persistent nasal discharge and infection. Conversely, primary maxillary sinusitis can lead to infected and enlarged adenoids.
4. Epistaxis: Acute inflammation of the adenoids can cause nosebleeds with nose blowing.
5. Voice Change: Nasal obstruction can make the voice toneless and devoid of its nasal quality.
6. Olfaction: Adenoidal hyperplasia may reduce olfactory sensitivity, particularly affecting retronasal smell and taste.

Aural Symptoms

1. Tubal Obstruction: An adenoid mass can block the eustachian tube, leading to a retracted tympanic membrane and conductive hearing loss.
2. Recurrent Acute Otitis Media: Infections can spread via the eustachian tube, causing recurrent episodes.
3. Chronic Suppurative Otitis Media: This condition may persist in the presence of infected adenoids.
4. Otitis Media with Effusion: Adenoids are a significant cause in children, with fluctuating sizes causing intermittent eustachian tube obstruction and fluctuating hearing loss. Impedance audiometry can help diagnose this condition.

General Symptoms

1. Adenoid Facies: Chronic nasal obstruction and mouth breathing lead to a characteristic appearance known as adenoid facies, marked by an elongated face, dull expression, open mouth, prominent and crowded upper teeth, hitched-up upper lip, and a pinched-in nose due to disuse atrophy of the alae nasi. The hard palate becomes highly arched as the tongue’s moulding action is lost.
2. Pulmonary Hypertension: Long-standing nasal obstruction due to adenoid hypertrophy can lead to pulmonary hypertension and cor pulmonale.
3. Aprosexia: Lack of concentration.

DIAGNOSIS

Examination of the postnasal space in some young children can reveal an adenoid mass using a mirror. A rigid or flexible nasopharyngoscope is also useful for detailed visualization in a cooperative child. A soft tissue lateral radiograph of the nasopharynx can reveal the size of the adenoids and the extent of nasopharyngeal air space compromise. A thorough nasal examination should be conducted to exclude other causes of nasal obstruction.

DIFFERENTIAL DIAGNOSIS

Differential diagnoses include choanal atresia, foreign bodies in the nose, nasopharyngeal angiofibroma, and malignant tumors of the nasopharynx, particularly of mesenchymal origin in children. Dental causes should also be considered to explain positional anomalies of the teeth and malocclusion.

TREATMENT

For mild symptoms, breathing exercises, decongestant nasal drops, and antihistamines for coexistent nasal allergy can alleviate the condition without surgery. For marked symptoms, adenoidectomy is indicated.

——– End of the chapter ——–

Reference Textbooks.

• Scott-Brown, Textbook of Otorhinolaryngology-Head and Neck Surgery.
• Cummings, Otolaryngology-Head and Neck Surgery.
• Stell and Maran’s, Textbook of Head and Neck Surgery and Oncology.
• Ballenger’s, Otorhinolaryngology Head And Neck Surgery
• Susan Standring, Gray’s Anatomy.
• Frank H. Netter, Atlas of Human Anatomy.
• B.D. Chaurasiya, Human Anatomy.
• P L Dhingra, Textbook of Diseases of Ear, Nose and Throat.
• Hazarika P, Textbook of Ear Nose Throat And Head Neck Surgery Clinical Practical.
• Mohan Bansal, Textbook of Diseases of Ear, Nose and Throat Head and Neck Surgery.
• Hans Behrbohm, Textbook of Ear, Nose, and Throat Diseases With Head and Neck Surgery.
• Logan Turner, Textbook of Diseases of The Nose, Throat and Ear Head And Neck Surgery.
• Arnold, U. Ganzer, Textbook of  Otorhinolaryngology, Head and Neck Surgery.
• Ganong’s Review of Medical Physiology.
• Guyton & Hall Textbook of Medical Physiology.

Author:

Dr. Rahul Bagla
MBBS (MAMC, Delhi) MS ENT (UCMS, Delhi)
Fellow Rhinoplasty & Facial Plastic Surgery.
Renowned Teaching Faculty
Mail: msrahulbagla@gmail.com
India

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