=====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 [[cephalocele]]s. They consisted of four encephaloceles, six meningoceles, and five atretic cephaloceles
((Yokota A, Kajiwara H, Kohchi M, Fuwa I, Wada H. Parietal cephalocele: clinical
importance of its atretic form and associated malformations. J Neurosurg. 1988
Oct;69(4):545-51. PubMed PMID: 3418387.
)).




====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
((Yokota A, Kajiwara H, Kohchi M, Fuwa I, Wada H. Parietal cephalocele: clinical
importance of its atretic form and associated malformations. J Neurosurg. 1988
Oct;69(4):545-51. PubMed PMID: 3418387.
)).