Presentation
A palpable scalp mass
Patient Data
Midline subgaleal cystic mass at the posterior fontanelle with intracranial extension is seen. The mass contains CSF with some linear structures representing most likely meninges with glial and neuronal rests. Persistent primitive falcine vein is seen which is vertically oriented to subcutaneous mass. High position of tentorium cerebelli with prominence of superior cerebellar cistern is also noted.
These findings are in keeping with atretic parietal cephalocele.
Case Discussion
Atretic parietal cephalocele is a subgaleal lesion that consists of dura, fibrous tissue and dysplastic brain tissue.
Radiographic findings include:
- 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 the superior cerebellar cistern and suprapineal recess
- superior peaking of the posterior tentorium
- spinning top configuration of the tentorial incisura
Differential diagnosis :
- sinus pericranii
- dermoid or epidermoid cyst
- cephalohematoma
- sebaceous cyst
- vascular lesions (hemangioma)