Background: Basal encephalocele is a rare entity of midline neural tube defect. Trans-sphenoidal encephalocele (TSE) is a
type of basal encephalocele protruding through the sphenoid bone.
Objective: To report clinical manifestation, radiographic findings and surgical treatment in a patient with TSE.
Material and Method: A 14-month-old baby was transferred to Siriraj Hospital with the suspicion of basal encephalocele after the surgical repair of cleft lip and cleft palate had been performed.
Results: Computerized tomography and magnetic resonance imaging of the head revealed a defect at the anterior cranial
fossa and sella floor with a protruded soft tissue mass. The complete radiological examination concluded the diagnosis of
TSE. Ophthalmic examination revealed posterior staphyloma and right optic nerve hypoplasia. Transcranial exploration of
the anterior skull base showed the protrusion of pituitary stalk and its content into the bony defect at sella turcica, lateral
attachment of the olfactory bulb, separated optic chiasm and bilateral optic nerve hypoplasia.
Conclusion: Basal encephalocele should be cautious when a soft tissue mass is found within the nasal cavity or at the roof of
the mouth in patients with craniofacial dysraphism.

Keywords: Trans-sphenoidal encephalocele, Craniofacial dyrhaphism, Craniopharyngeal canal