Adenoid hypertrophy is the physiologic or pathologic enlargement of the lymphoid tissue (adenoid or pharyngeal tonsil) in the nasopharynx. As part of the Waldeyer lymphoid ring, adenoid tissue physiologically enlarges between ages 2-6 during immune system development and naturally involutes after puberty. It is the most common cause of nasopharyngeal airway obstruction and can lead to obstructive sleep apnea, chronic mouth breathing, sinusitis, and serous otitis media. On CT/MRI, it appears as symmetric, homogeneous nasopharyngeal soft tissue thickening. On lateral radiograph, the adenoid/nasopharynx (A/N) ratio grades airway narrowing. Asymmetric or aggressive growth, especially in adult patients, should raise suspicion for lymphoma or NPC and may require biopsy. In radiological evaluation, symmetry, homogeneity, and absence of bone erosion are the most important benignity criteria.
Age Range
2-12
Peak Age
5
Gender
Equal
Prevalence
Very Common
Adenoid tissue is lymphoid tissue located on the posterior superior wall of the nasopharynx and is part of the Waldeyer ring. It enlarges through lymphoid follicular hyperplasia and germinal center expansion in response to antigenic stimulation. Physiologic growth peaks between ages 2-6 — during this period children experience intense antigenic exposure (viral/bacterial upper respiratory infections) and adenoid tissue hypertrophy develops as immune response. After puberty, hormonal changes and immune system maturation initiate natural involution. Homogeneous enhancement on CT/MRI reflects the adenoid tissue's dense vascular architecture — homogeneous gadolinium distribution from regular capillary bed. Symmetric growth pattern reflects diffuse hyperplasia of all lymphoid tissue and indicates absence of focal mass (NPC/lymphoma). Absence of bone erosion confirms that growth is expansile (pushing) rather than infiltrative (destructive).
Symmetric, homogeneous, well-defined soft tissue thickening in the nasopharynx of a pediatric patient — combined with absence of bone erosion and necrosis, this is the signature finding of adenoid hypertrophy. In the presence of asymmetry, lymphoma/NPC should be considered and biopsy planned.
Symmetric, homogeneously enhancing soft tissue thickening in the nasopharynx. Adenoid tissue appears as diffuse thickening covering the posterior-superior nasopharyngeal wall. Enhancement is homogeneous — does not contain necrosis or cystic areas. Margins are smooth or mildly lobulated. No bone erosion.
Report Sentence
Symmetric, homogeneously enhancing soft tissue thickening is identified in the nasopharynx consistent with adenoid hypertrophy; no bone erosion or focal mass is detected.
Symmetric nasopharyngeal tissue thickening showing isointense or mildly hyperintense signal to muscle on T2. Isointense to muscle on T1. Homogeneous signal pattern — no necrosis or cystic component. Symmetric distribution is characteristic of lymphoid hyperplasia.
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Symmetric soft tissue thickening in the nasopharynx showing isointense signal to muscle on T1 and mildly hyperintense on T2 is identified, consistent with adenoid hypertrophy.
Nasopharyngeal airway lumen narrowing — expansion of adenoid tissue narrows the posterior nasopharyngeal airway. Grading on lateral radiograph by adenoid (A) / nasopharynx (N) ratio: Grade I (A/N <0.5), Grade II (A/N 0.5-0.75), Grade III (A/N >0.75). On CT, airway narrowing can be directly measured on axial and sagittal reformats.
Report Sentence
The nasopharyngeal airway is significantly narrowed due to adenoid tissue hypertrophy (Grade ___) and should be correlated with clinical obstructive symptoms.
No significant diffusion restriction on DWI — cellularity in adenoid tissue is lower compared to malignant lesions. ADC value is within normal lymphoid tissue range (>1.2 × 10⁻³ mm²/s). Significant diffusion restriction (ADC <0.8) is interpreted in favor of lymphoma or NPC.
Report Sentence
The adenoid tissue demonstrates no significant diffusion restriction on DWI (ADC: ___ × 10⁻³ mm²/s), consistent with benign lymphoid hyperplasia.
Soft tissue thickening on the posterior nasopharyngeal wall on lateral pharyngeal US. US can be used as a radiation-free alternative for adenoid size assessment — especially preferred in pediatric population. Adenoid tissue appears hypoechoic/isoechoic with homogeneous structure.
Report Sentence
Homogeneous soft tissue measuring ___ mm in thickness is identified on the posterior nasopharyngeal wall, consistent with adenoid hypertrophy.
Criteria
A/N ratio <0.5. Airway narrowed less than 50%. Usually asymptomatic.
Distinct Features
No treatment required, follow-up sufficient. Evaluated with clinical correlation.
Criteria
A/N ratio 0.5-0.75. Airway narrowed 50-75%. Mouth breathing and snoring symptoms.
Distinct Features
Medical treatment (intranasal steroid) or adenoidectomy evaluated based on symptom severity.
Criteria
A/N ratio >0.75. Airway narrowed >75%. Obstructive sleep apnea, significant mouth breathing.
Distinct Features
Strong adenoidectomy indication. Sleep study (PSG) for OSA grading recommended. Facial dysmorphism (adenoid facies) may develop.
Distinguishing Feature
NPC is asymmetric, infiltrative, bone erosion, adult age; adenoid hypertrophy is symmetric, homogeneous, no bone erosion, pediatric
Distinguishing Feature
Lymphoma may be asymmetric, marked DWI restriction (ADC <0.8), adult age; adenoid hypertrophy is symmetric, no DWI restriction
Distinguishing Feature
Thornwaldt is focal midline cystic lesion; adenoid hypertrophy is diffuse solid tissue thickening
Urgency
routineManagement
conservativeBiopsy
Not NeededFollow-up
specialist-referralAdenoid hypertrophy is very common in the pediatric population and most cases show spontaneous involution. Surgical indication (adenoidectomy): obstructive sleep apnea, chronic sinusitis, recurrent acute otitis media, and serous otitis media. Intranasal steroids are a medical alternative in mild-moderate cases. Asymmetric growth or nasopharyngeal tissue thickening in adult patients is a biopsy indication for lymphoma/NPC.
Adenoid hypertrophy is the most common cause of obstructive sleep apnea, mouth breathing, chronic sinusitis, and serous otitis media in children. Treatment indications include obstructive sleep apnea, chronic sinusitis, and recurrent otitis media. Surgical treatment is adenoidectomy. Asymmetric growth, especially in adults, requires biopsy for lymphoma suspicion.