Atretic cephalocele
Also known as Atretic parietal cephalocele, refers to small subscalp lesions that consist of dura, fibrous tissue, and dysplastic brain tissue.
Epidemiology
Common presentation in infants and young children.
In 15 infants (10 boys and five girls), accounted for 37.5% of all cephaloceles. They consisted of four encephaloceles, six meningoceles, and five atretic cephaloceles 1).
Clinical presentation
Palpable midline parietal soft tissue mass.
Pathology
It is thought to represent involuted true cephalocele (meningocele or encephalocele) connected to dura mater via a fibrous stalk.
Associations
Increased incidence of intracranial anomalies.
Radiographic features
Subgaleal soft tissue mass with intracranial extension via sharply demarcated calvarial defect (cranium bifidum)
CSF tract and vertical falcine vein point to the subcutaneous scalp mass.
Vertically oriented primitive falcine vein
Fibrous stalk connecting the cephalocele
Focal fenestration of superior sagittal sinus at the atretic parietal cephalocele
Prominence of superior cerebellar cistern and suprapineal recess
Superior peaking of the posterior tentorium
Spinning top configuration of the tentorial incisura
Differential diagnosis
Imaging differential considerations include
Sinus pericranii
Dermoid or epidermoid cyst
Cephalohaematoma
Sebaceous cyst
Vascular lesions (haemangioma)
Treatment and prognosis
Parietal cephaloceles carried a much less favorable prognosis than those in the occipital region, regardless of the type of cephalocele; they were associated with cerebral malformations more frequently and were more severe than occipital cephaloceles. Grave congenital anomalies were found in 87% of patients with parietal cephalocele, and only two patients (neither of whom had any other malformation) attained normal development. Brain malformations were closely related to the site from which the cephalocele issued, and dorsal cyst malformation was found in eight patients with parietal cephalocele. Two types of atretic cephaloceles were found, each in a different location. The first type was an alopecic lesion occurring in the parietal midline; all five patients with this type had dorsal cyst malformations and none developed normally. The second type was a nodular lesion developing at the occipital midline, not associated with cerebral anomalies; all five patients with this type showed normal development 2).