Tonsillar hypertrophy is benign lymphoid tissue enlargement of the palatine tonsils and the most commonly encountered pharyngeal pathology in childhood. It results from enlargement of Waldeyer's ring lymphoid tissue in response to immunological stimulation (recurrent infections, allergy). Prevalence is highest in the 3-8 year age group, and natural regression is expected after puberty. Obstructive sleep apnea syndrome (OSAS) is the most important complication in the pediatric population. On CT and MRI, bilateral symmetric tonsillar enlargement, homogeneous enhancement, and preserved tonsillar crypts are diagnostic clues. Asymmetric enlargement must always exclude malignancy (especially lymphoma and SCC) — biopsy indication arises in this situation.
Age Range
2-40
Peak Age
8
Gender
Equal
Prevalence
Very Common
Tonsillar hypertrophy results from physiological/excessive response of lymphoid tissue in the palatine tonsils to antigenic stimulation. The tonsils are part of Waldeyer's ring and serve immune surveillance at the intersection of the oropharynx and nasal-oral airway. In childhood, frequent recurrent upper respiratory infections, allergens, and environmental irritants lead to germinal center hyperplasia — B lymphocyte proliferation and antibody production increase. During this process, tonsil volume increases significantly and crypts widen. Homogeneous enhancement results from increased vascularity (lymphoid tissue hypervascularity); necrosis and calcification are not expected because tissue integrity is preserved. Symmetric enlargement is the most reliable indicator of a reactive/physiological process — asymmetry should suggest malignant infiltration (especially lymphoma) because lymphoma cells disrupt normal lymphoid architecture causing unilateral expansion. With puberty, natural involution occurs due to maturation of the immune system.
In advanced tonsillar hypertrophy, bilateral tonsils contact each other at the midline — termed 'kissing tonsils'. This indicates significant airway obstruction and strengthens the indication for adenotonsillectomy. On axial CT sections, the intertonsillar distance measures 0 mm.
Contrast-enhanced CT shows symmetric enlargement and homogeneous enhancement of bilateral palatine tonsils. Tonsillar tissue is isodense to muscle or may be mildly hypodense. There are no findings of internal necrosis, calcification, or irregular enhancement. Tonsillar crypts may be widened and crypt content may appear low density. The oropharyngeal airway is bilaterally narrowed with medialized tonsils. Parapharyngeal fat planes are preserved — no invasion signs.
Report Sentence
Symmetric enlargement and homogeneous enhancement is noted in bilateral palatine tonsils, consistent with tonsillar hypertrophy/lymphoid hyperplasia.
On MRI T2-weighted sequences, bilateral tonsils are symmetrically enlarged showing mildly hyperintense homogeneous signal. Lymphoid tissue shows mild T2 prolongation compared to muscle due to rich fluid content (germinal center matrix). No internal necrosis or cystic change areas are seen. Tonsillar crypts may be identified as thin high-signal lines on T2.
Report Sentence
MRI T2-weighted sequences demonstrate symmetric enlargement and mildly hyperintense homogeneous signal in bilateral palatine tonsils; no DWI restriction suggestive of malignancy was detected.
No diffusion restriction is expected in tonsillar hypertrophy on DWI. ADC values are in the normal range and significantly higher compared to high-cellularity malignancies like lymphoma. This feature is critically important in distinguishing tonsillar hypertrophy from tonsillar lymphoma; lymphoma shows marked diffusion restriction and low ADC values due to increased cellularity.
Report Sentence
No diffusion restriction was detected in bilateral tonsils on DWI; ADC values are within normal limits.
On non-contrast CT, bilaterally enlarged tonsils symmetrically narrow the oropharyngeal airway. The tonsils are medialized and approach each other; in advanced cases, tonsils may contact at the midline ('kissing tonsils'). Airway cross-sectional area is significantly reduced. If accompanying adenoid hypertrophy is present, the nasopharyngeal airway may also be narrowed. The degree of airway narrowing correlates with clinical symptoms (snoring, OSAS).
Report Sentence
Bilaterally enlarged palatine tonsils significantly narrow the oropharyngeal airway with a residual airway diameter of approximately ... mm.
On intraoral or transcervical US, tonsils appear as hypoechoic homogeneous tissue. Normal tonsillar echo structure is preserved with no internal heterogeneity, cystic areas, or calcification. Doppler may show normal or mildly increased vascularity (reflecting reactive hyperemia). Tonsil size can be measured by US and compared with the contralateral side — symmetry assessment is important for malignancy exclusion.
Report Sentence
On US, bilateral palatine tonsils are hypoechoic and homogeneous with symmetric enlargement; no internal heterogeneity or abnormal vascularity pattern was detected.
Criteria
Palatine tonsils + adenoid (nasopharyngeal tonsil) enlarged together
Distinct Features
Both oropharyngeal and nasopharyngeal airways are narrowed; most common cause of pediatric OSAS
Criteria
Only palatine tonsils enlarged, adenoid normal
Distinct Features
Oropharyngeal airway narrowing predominant; dysphagia more prominent
Criteria
Lingual tonsil enlargement at the tongue base
Distinct Features
May present as tongue base mass; vallecula obliteration; can cause intubation difficulty
Distinguishing Feature
Lymphoma shows unilateral enlargement with marked DWI restriction + low ADC; hypertrophy is symmetric with no DWI restriction
Distinguishing Feature
Abscess shows rim-enhancing hypodense collection; hypertrophy is solid homogeneous tissue
Distinguishing Feature
SCC is asymmetric with necrosis and ulceration, has invasive margins; hypertrophy is symmetric and smooth-bordered
Urgency
routineManagement
conservativeBiopsy
Not NeededFollow-up
specialist-referralSymptomatic tonsillar hypertrophy (OSAS, dysphagia) warrants ENT referral. Polysomnography determines the degree of OSAS. Adenotonsillectomy is curative in symptomatic cases. In asymmetric enlargement, biopsy is indicated to exclude malignancy.
Tonsillar hypertrophy is the most common cause of obstructive sleep apnea in children. Asymmetric or markedly unilateral enlargement should raise suspicion for malignancy. Adenotonsillectomy is indicated in symptomatic cases.