cephalocele – frontoethmoidal

cephalocele – frontoethmoidal

cephalocele - fronto ethmoid
cephalocele – fronto ethmoid note the small echofree cranial defect at the vertex.; note the small echofree cranial defect at the vertex.; note the small echofree cranial defect at the vertex.
encephalocele-frontoethmoidal
encephalocele-frontoethmoidal a very large frontal defect containing cerebral tissue is clearly seen. note the displaced remaining intracranial structures.; a very large frontal defect containing cerebral tissue is clearly seen. note the displaced remaining intracranial structures.
cephalocele - fronto ethmoid
cephalocele – fronto ethmoid coronal view of face showing a large echogenic mass between the orbits. note there is no clefting.; coronal view of face showing a large echogenic mass between the orbits. note there is no clefting.
cephalocele frontoethmoidal
cephalocele -frontoethmoidal the bony skull defect is in the frontal region and so does not cause hypertelorism. cerebral tissue protrudes through the defect.; the bony skull defect is in the frontal region and so does not cause hypertelorism. cerebral tissue protrudes through the defect.
cephalocele - fronto ethmoid
cephalocele – fronto ethmoid the mass is clearly seen at the level of the orbits, above the nose.; the mass is clearly seen at the level of the orbits, above the nose.

description

cephalocele is the protrusion of intracranial contents through a bony defect in the skull. originally considered as one of the varied manifestations of failed neural tube closure such as anencephaly or spina bifida, epidemiologic data suggests that isolated frontoethmoidal cephalocele is a pathogenetically distinct condition. families with this malformation are not at increased risk for neural tube defect in subsequent offspring, but may present with other central nervous system anomalies (6%). thailand has an unusually high incidence of frontal cephaloceles.

diagnosis

a sac protruding through an anterior cranial defect may be seen on a sagittal or transverse views through the orbital region. hypertelorism may result. although most frontoethmoidal cephaloceles are sporadic, occasionally they occur in conjunction with known genetic syndromes, and may present with characteristic associated defects. for example, in roberts syndrome, an autosomal recessive disorder, there may be associated growth restriction, limb reduction defects, cleft lip and/or palate.

differential diagnosis

frontonasal dysplasia (median facial cleft syndrome), which may be inherited as an autosomal dominant condition, may present with a frontal encephalocele in addition to the characteristic findings of a notched and broad nasal tip, hypertelorism and median cleft palate. amniotic band sequence is a sporadic condition in which fragments of ruptured amnion may cause fetal deformation, including encephalocele formation, cleft lip and amputation of the extremities. most frontoethmoidal cephaloceles are closed, skin covered defects. failure of endochondral bone development in atelosteogenesis, a generalised lethal chondrodysplasia, has also resulted in frontal cranial defects.

sonographic features

hypertelorism with lateral displacement of orbits by mass which emerges from an anterior cranial defect, and is usually skin covered associated anomalies may include micromelia (atelosteogenesis), median facial clefting (frontonasal dysplasia).

associated syndromes

  • apert
  • chromosome abnormalities
  • cranio-telencephalic dysplasia
  • fraser
  • fronto-facio-nasal dysplasia
  • frontonasal dysplasia
  • knobloch-vitreoretinopathy
  • oculo-cerebro-cutaneous
  • roberts-sc phocomelia
  • scalp defect-craniostenosis
  • amniotic bands

references

1. budorick ne, pretorius dh, mcgahan jp, grafe mr, james he, slivka j cephalocele detection in utero: sonographic and clinical features ultrasound obstet gynecol 5: 77-85