Types of Encephalocele by Location
Transethmoidal encephalocele
A transethmoidal encephalocele is a basal encephalocele that herniates through the ethmoid bone (cribriform plate) into the nasal cavity.
In short: Transethmoidal encephalocele
- It protrudes into the nose through the cribriform plate.
- It may present as a nasal mass.
- It must be imaged before any biopsy.
- It is part of the differential diagnosis for a nasal mass.
What it is
It is a basal encephalocele protruding through the ethmoid bone — specifically the cribriform plate — into the nasal cavity. It commonly appears as a mass inside the nose.
Understanding Transethmoidal encephalocele
Because it appears as a nasal mass, it is part of the differential diagnosis for nasal swellings, alongside nasal glioma and dermoid cyst, and it requires imaging first to avoid a CSF leak and meningitis. The cribriform plate is the perforated region through which the smell nerves pass, so this area sits directly between the brain and the nose. Repair is often endoscopic.
Why it matters
Understanding that a transethmoidal encephalocele can look like a simple nasal mass — but connects to the brain — reinforces why imaging precedes any biopsy of a nasal swelling. This caution prevents a dangerous procedure.
Common questions
Where does it protrude?
Into the nasal cavity through the cribriform plate.
Why image before biopsy?
It may connect to the brain and contain CSF.
What else can a nasal mass be?
A nasal glioma or dermoid cyst, among others.
Bottom line
A transethmoidal encephalocele protrudes into the nose through the ethmoid and must be imaged before biopsy.
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