Lingual tonsillar hypertrophy

• lingual tonsils are rounded masses of lymphatic tissue that cover the posterior region of the tongue
  • located on the dorsal surface at the base of the tongue
    • lingual tonsils exist at the base of the tongue and are bounded by the epiglottis posteriorly, vallate papillae anteriorly, and tonsillar pillars bilaterally
  • lymphatic tissue is dense and nodular, their surface is covered with stratified squamous epithelium which invaginates as a single crypt into each lingual tonsil
  • lingual tonsils are partially surrounded by connective tissue
  • lingual tonsils have associated mucous glands which are drained by ducts directly into the single tonsillar crypt

Click here for image of lingual tonsils

Lingual tonsillar hypertrophy

• the cause of lymphoid hyperplasia of the lingual tonsils is most likely a chronic, low-grade infection of the tonsils
  
  
• is a life-threatening cause of unknown difficult intubations (1)
  
  
• lingual tonsillar hypertrophy most commonly occurs in adults, although it may occur in children
  • lingual tonsil hypertrophy can be asymptomatic, but can be associated with vague symptoms including sore throat, dysphagia, snoring, globus sensation, and obstructive sleep apnoea
  • a nonproductive chronic cough caused by irritation of the pharynx by the lingual tonsils may occur
  • reported complications include airway obstruction abscess formation, sleep apnoea, and recurrent epiglottitis and diffficult anaesthetic intubations
    • lingual tonsil hypertrophy is being increasingly recognized as a cause of both unexpected difficult intubation and difficult mask ventilation
      • danger of Lingual tonsil hypertrophy lies in the fact that traditional preoperative oropharyngeal examination fails to hint at the difficulties that may be encountered following induction of general anesthesia and muscle relaxation
      • in addition, following muscle relaxation lingual tonsils may act as a 'ball valve' that prohibits antegrade ventilation or insertion of an endotracheal tube
• best way to diagnose lingual tonsillar hypertrophy is through indirect or fiberoptic laryngoscopy
  
  
• a differential diagnosis of enlarged lingual tonsils includes lymphoma, lingual thyroid, granular cell myoblastoma, and metastatic lung adenocarcinoma

Reference:

• 1) Schroeder K et al. Severe lingual tonsillar hypertrophy and the rationale supporting early use of wire-guided retrograde intubation. Saudi J Anaesth. 2010 May;4(2):102-4.
• 2) Jones DH, Cohle SD. Unanticipated difficult airway secondary to lingual tonsillar hyperplasia. Anesth Analg. 1993 Dec;77(6):1285-8.