Basal encephalocele

What it means

Basal encephalocele is an encephalocele that occurs along the cribriform plate or through the sphenoid bone. The mass may appear in the nasal cavity, nasopharynx, epipharynx, sphenoid sinus, posterior orbit, or pterygopalatine fossa. The important distinction from other types is that no external tumor is visible except in those rare instances of herniations so large that they protrude through the mouth or nares.

The skull base is made up of the ethmoid, sphenoid, occipital, paired frontal, and paired parietal bones, and is subdivided into 3 regions: the anterior, middle, and posterior cranial fossae.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category