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9 y.o. with superficial nasal soft tissue mass.

Findings

Soft tissue mass projects out of the anterior cranial fossa, through the foramen cecum, and into the nasopharynx.

CSF surrounds the soft tissue lesion.

Abnormal facial bones.

Differential Diagnosis

Nasal Epidermoid / Dermoid

Nasal Glioma (Benign Congenital Nasal Neuroectodermal Tumor)

Anterior Encephalocele

Anterior Encephalocele

Congenital herniation of intracranial contents through a cranial defect.

Those containing meninges are designated meningoceles. Containing brain; a meningoencephalocele.

Cephaloceles are classified by the site of the cranial defect through which the brain and meninges protrude.

Sincipital cephaloceles are situated in the anterior part of the skull.

Anterior Encephalocele

Sincipital cephaloceles include both interfrontal cephaloceles and frontoethmoidal cephaloceles.

Always present as external masses along the nose, orbital margin, or forehead.

1 per 4000 live births, vary widely in different populations.

Found in 1 in 35,000 live births in North America and Europe but in 1 per 5000 to 6000 live births in Southeast Asia.

Anterior Encephalocele

Among Caucasians, occipital cephaloceles are most frequent, while sincipital cephaloceles and basal cephaloceles are infrequent. Among Australian aborigines, Malaysians, and select Southeast Asian groups, sincipital cephaloceles are the most frequent form encountered.

Occipital cephaloceles are closely linked with neural tube defects such as myelomeningoceles and show a female preponderance (2.4;1).

Sincipital cephaloceles show no linkage to neural tube defects and no gender predominance.

Interfrontal Cephalocele

The interfrontal cephalocele presents anteriorly as a midline mass situated above the frontonasal suture. In this form, the cranial defect lies between the two frontal bones.

Frontoethmoidal Cephalocele

Frontoethmoidal cephaloceles are defined as cephaloceles that pass outward from the skull through a defect at the junction of the frontal and ethmoid bones, immediately anterior to the crista galli.

Futher subclassified into nasofrontal, nasoethmoidal, and nasoorbital subtypes by the point at which the skull defect and hernia emerge externally.

Frontoethmoidal Cephalocele

The relative frequencies of the individual subtypes of frontoethmoidal cephaloceles may vary with the population.

In a study population of 120 cases of frontoethmoidal cephaloceles from Southeast Asia, 40% were frontonasal, 42% were nasoethmoidal, and 18% were nasoorbital.

In 30 cases from India, however, only 7% were frontonasal, 87% were nasoethmoidal, and 6% were nasoorbital.

Frontoethmoidal Cephalocele

Frontoethmoidal cephaloceles induce secondary deformities in the facial skeleton.

Impede development of the frontal sinuses, and increase the interorbital and intercanthal distances in most cases.

Displacement of the crista galli, the cribriform plate, and the perpendicular plate of the ethmoid bone may lead to maxillary hypoplasia.

In all cases, the face appears longer than normal and the nasal cartilages are misshapen.

Frontoethmoidal Cephalocele

Concurrent malformations found in patients with frontoethmoidal cephaloceles include microcephaly, unilateral or bilateral microphthalmos, syndactyly with appendicular constriction bands, hydrocephalus, and seizures.

Mental retardation (43%) of those old enough to test.

CSF leakage and bleeding from the exposed brain can be problematic in those cephaloceles lacking a skin cover or in which the skin cover has ruptured.

Frontoethmoidal Cephalocele

Etiologies have not been established.

Clear variations in cephalocle incidence with geographic location and population suggest the possibility of a genetic basis.

Advanced paternal age?

Autosomal Dominant inheritance pattern?

Aflatoxins, notably ochratoxin A, may represent a teratogenic cause?

Frontoethmoidal Cephalocele

Approximately 60% to 85%of frontoethmoidal cephaloceles have a good outcome unless there are concurrent severe anomalies.

The size of the fluid spaces does not determine the patient’s prognosis.

The role of imaging is to display the bony defect, the nature of the herniating tissue, the effect on the adjacent tissue, and any concurrent ENT malformations.