Nasopharyngeal mass

Considerations

• • Histology of the nasopharynx (NP) (2013: Uncommon Presentation of a Benign Nasopharyngeal Mass in an Adolescent: Comprehensive Review of Pediatric Nasopharyngeal Masses)

    • Stratified squamous epithelium at the anterior, posterior, and inferior walls 

    • Respiratory epithelium at the roof and nasal choanae

    • The remaining areas have mixtures of squamous and respiratory or intermediate (transitional) epithelium

    • There is abundant lymphoid tissue present, particularly at the rim of eustachian tube opening, which is functionally equivalent to that of gastrointestinal tract or mucosal-associated lymphoid tissue 

• Epidemiology 

  • • Benign NP tumors are rare (2011: Benign Tumours of Nasopharynx—Revisited)

    • Most common in children and young adults 

    • More common in males

• • Common symptoms 

    • Most common

      • Nasal obstruction

      • Epistaxis 

    • Less common

      • Post nasal drip

      • Aural fullness

      • Trismus

      • Hyposmia 

  • Differential

    • Non-tumor masses

      • Adenoid hypertrophy 

      • Adenoid retention cyst 

    • Antrochoanal polyp (ACP)

    • Branchial cleft cyst

      • Encephalocele or Meningocele or Meningomyelocele

      • Ectopic (heterotopic) brain tissue 

    • Fibrous dysplasia (2001: Fibrous dysplasia involving the skull base and temporal bone)

    • Internal carotid artery (1998: Internal carotid artery aneurysm presenting as an unusual nasopharyngeal mass)

    • Nasopharyngeal lymphoid proliferation / hypertrophy (in high-risk patients can be an early sign of HIV infection) (1990: Benign Nasopharyngeal Masses and Human Immunodeficiency Virus Infection)

    • Rathke's cleft cyst 

    • Thornwald (aka Thornwaldt, Tornwaldt) cyst or bursa - most common epithelial lesion after adenoid hypertrophy 

  • Benign tumors

    • Most common benign tumor: Juvenile nasopharyngeal angiofibroma (JNA)

    • Chondroma

    • Chordoma

    • Craniopharyngioma

      • Dermoid

    • Fibroma

    • Glioma 

      • Hemangioma

      • Hemangiopericytoma

      • Rhabdomyoma 

      • Squamous papilloma 

      • Teratoma ("hairy polyp of nasopharynx") and Epignathus

  • Malignancy

    • Carcinoma

    • Rhabdomyosarcoma

    • Lymphoma 

    • Lymphoepithelioma

    • Lymphosarcoma 

    • Melanoma (2014: Primary mucosal malignant melanoma of nasopharynx: a rare case report)

• Imaging 

  • • Keep in mind four facial planes (1980: CT Approach to Benign Nasopharyngeal Masses)

      • prevertebral fascia

      • pharyngobasilar fascia

      • carotid sheath

      • buccopharyngeal fascia

    • Both CT and MRI may be warranted  

• Surgical approach is determined by the tumor size and extent 

• • External - increased morbidity 

    • Inferiorly—via a trans-palatal route

    • Laterally via a transtemporal or infratemporal route

    • Anteriorly via a maxillary swing

  • Transnasal endoscopic - excellent visualization, limited anatomical limit