Unknown/Occult Primary Cancers (CUP) of Head & Neck: Panendoscopy, biopsies and tonsillectomy

Prior imaging to direct biopsies to suspicious areas increases diagnostic yield
Nasopharynx
- Normal nasopharyngoscopy findings: no need to biopsy
- Biopsy nasopharynx under local (LA) or general anaesthesia (GA) if
  - Suspicious nasopharyngoscopy findings
  - Suspicious CT or MRI
  - EBV +ve node
  - Nasopharyngoscopy not available / mirror exam only
  - Level V nodes & otitis media with effusion (OME)
Panendoscopy
- Oesophagoscopy, laryngoscopy, pharyngoscopy
- Palpate tonsils and base of tongue
- Re-examine looking for bleeding after initial palpation of tonsil and base of tongue and retraction of tonsillar pillars
Tissue biopsies
- Biopsy clinically or radiologically suspicious areas
- Some advocate transoral lingual tonsillectomy: robotic / non-robotic with Lindholm scope, telescope, and extension on long Bovie tip
- Note
  - May be impossible to distinguish normal lingual / pharyngeal tonsil tissue from HPV related basaloid SCC
  - Primary may be hidden in tonsillar crypts
- If imaging not readily available / unhelpful
  - Bilateral tonsillectomy (10 – 23% contralateral tonsil primary)
  - Multiple biopsies of base of tongue or lingual tonsillectomy with CO2 laser / electrocautery / TORS