Zephalozele

Atretic

parietal cephalocele • Atretic occipital cephalocele - Ganzer Fall bei Radiopaedia

Abdo T, Atretic occipital cephalocele. Case study, Radiopaedia.org (Accessed on 02 Jan 2023) https://doi.org/10.53347/rID-83154 • CC by-nc-sa 3.0 (modified)

Magnetic

resonance imaging of sellar and juxtasellar abnormalities in the paediatric population: an imaging review. Cephalocele in a 17-year-old girl. Coronal T2WI (a) and sagittal T1WI (b) shows a meningocele extending inferiorly into the nasopharynx through an osseous defect in the sphenoid bone posterior to the pituitary gland

insightsimaging.springeropen.com • Open Access

Cephalocele

• Atretic cephalocele - Ganzer Fall bei Radiopaedia

Ibrahim D, Atretic cephalocele. Case study, Radiopaedia.org (Accessed on 02 Jan 2023) https://doi.org/10.53347/rID-28711 • CC by-nc-sa 3.0 (modified)

Cephalocele

• Occipital cephalocele - Ganzer Fall bei Radiopaedia

Hosseinabadi F, Occipital cephalocele. Case study, Radiopaedia.org (Accessed on 02 Jan 2023) https://doi.org/10.53347/rID-74199 • CC by-nc-sa 3.0 (modified)

Radiopaedia • CC-by-nc-sa 3.0 • de

Cephalocele refers to the outward herniation of CNS contents through a defect in the cranium. The vast majority are midline.

Epidemiology

The estimated incidence is 0.8-4:10,000 live births with a well recognized geographical variation between types; however, this has been speculated to be underestimated as many may result in elective termination, in utero demise, or stillbirth. There may be a female predilection .

Clinical presentation

The presentation may vary widely depending upon the type of defect.

Examples include:

large mass seen extending from cranium on prenatal ultrasound
small cranial soft tissue mass palpated in childhood (e.g. atretic cephalocele)
in utero demise (severe defect)

Pathology

It is thought to arise due to failed closure of the rostral end of the neuropore. This may result from either overgrowth of neural tissue in the line of closure, or failure of induction by adjacent mesodermal tissues which interferes with normal skull closure.

Classification

Cephaloceles can be classified into 5 types, based upon the herniated contents :

meningocele: CSF lined by meninges
gliocele: CSF lined by glial tissue
meningoencephalocele: CSF, brain, and meninges
meningoencephalocystocele: CSF, brain, meninges, and part of a ventricle and choroid plexus
atretic cephalocele: dura, fibrous tissue, and degenerated brain

Location

occipital cephalocele: most common, up to 75%
parietal cephalocele: up to 37%
frontal cephalocele/fronto-ethmoidal cephalocele: ~10%, this type is most common in Asia
petrous apex cephalocele : rare
intra sphenoidal cephalocele : rare

Associations

Additional congenital anomalies may be present in up to 50 % of cases. They include

aneuploidic
- trisomy 13
- trisomy 18
non-aneuploidic syndromic
- Meckel-Gruber syndrome: occipital
- Walker-Warburg syndrome
- fronto-nasal dysplasia
non-syndromic CNS anomalies
- fetal hydrocephalus/neonatal hydrocephalus
- microcephaly: ~20% of cases
- Dandy-Walker continuum
- dysgenesis of corpus callosum
- spina bifida
non-syndromic non-CNS anomalies
- cleft lip and palate
- congenital cardiovascular anomalies
- hypertelorism
- amniotic band syndrome : if there is an unlucky slash defect around the occipital region

Markers

maternal serum alpha-fetoprotein (MSAFP) may be elevated

Radiographic features

Ultrasound

Sonographically, these lesions may appear as:

a cyst protruding from the fetal calvarium representing a meningocele or cyst within cyst appearance
a solid mass protruding from the calvarium representing a herniated brain: encephalocele
either or both of the above associated with a defect in the calvarium

Treatment and prognosis

The overall prognosis is variable dependent on severity and other associations (presence of hydrocephalus, microcephaly, etc). If a large cephalocele is noted in an antenatal ultrasound scan, it generally implies a poor prognosis.