Pharyngeal Mucosal Space



Pharyngeal Mucosal Space


H. Ric Harnsberger, MD



Terminology


Abbreviations



  • Pharyngeal mucosal space (PMS)


Definitions



  • PMS: Nasopharyngeal, oropharyngeal & hypopharyngeal surface structures on airway side of middle layer of deep cervical fascia


Imaging Anatomy


Overview



  • PMS is conceptual construct to complete map of spaces of suprahyoid neck



    • PMS alternative term: Pharyngeal mucosal surface


  • There is no fascia on surface of PMS, so it is not a true fascia-enclosed space


Extent



  • PMS is a continuous mucosal sheet defined from nasopharynx to hypopharynx (includes soft palate)


  • Nasopharyngeal, oropharyngeal & hypopharyngeal mucosal space components



    • See larynx anatomy for hypopharynx anatomy


Anatomy Relationships



  • Airway side of PMS has no fascial border


  • Posterior to PMS is retropharyngeal space (RPS)


  • Lateral to PMS is parapharyngeal space (PPS)


  • Skull base relationship to PMS



    • Broad area of attachment to skull base present


    • Attachment area includes posterior basisphenoid (sphenoid sinus floor), anterior basiocciput (anterior clivus)


    • Also includes foramen lacerum



      • Foramen lacerum: Cartilaginous floor of anterior horizontal petrous internal carotid artery


      • Represents perivascular route for nasopharyngeal carcinoma to access intracranial structures


Internal Structures-Critical Contents



  • Mucosal surface of pharynx


  • PMS lymphatic ring: Lymphatic ring of tissue of PMS that declines in size with advancing age



    • Synonym: Waldeyer ring


    • Nasopharynx: Adenoids


    • Oropharynx, lateral wall: Palatine (faucial) tonsil


    • Oropharynx, base of tongue: Lingual tonsil


  • Minor salivary glands



    • Soft palate mucosa has highest concentration


  • Pharyngobasilar fascia



    • Tough aponeurosis that connects superior constrictor muscle to skull base


    • Posterosuperior margin notch = sinus of Morgagni



      • Levator palatini muscle & eustachian tube pass through this notch on way from skull base to PMS


  • Pharyngeal mucosal space muscles



    • Superior, middle & inferior constrictor muscles


    • Salpingopharyngeus muscle


    • Levator palatini muscle, distal end


  • Torus tubarius: Cartilaginous end of eustachian tube


Fascia of Pharyngeal Mucosal Space



  • Middle layer, deep cervical fascia (ML-DCF) represents deep margin of PMS



    • In nasopharynx ML-DCF encircles lateral & posterior margins of pharyngobasilar fascia


    • In oropharynx ML-DCF on deep margin of superior & middle constrictor muscles


    • In hypopharynx ML-DCF on deep margin of inferior constrictor muscle

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Jul 5, 2016 | Posted by in HEAD & NECK IMAGING | Comments Off on Pharyngeal Mucosal Space

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