Also known by various other names : leptomeningeal cyst, traumatic meningocoele, cerebrocranial erosion, cephalohydrocoele, meningocoele spuria, etc.

Growing skull fractures usually occur after severe head trauma during the first three years of life (particularly in infancy) and almost never after 8 yrs of life.

During this stage, the brain volume is increasing rapidly which is in part responsible for their development. Though the development of growing skull fractures is multifactorial but the predominant factor in their causation is the presence of lacerated duramater. The pulsatile force of the brain during its maximum growth will cause cerebral or subarachnoid herniation through the lacerated dura which causes the fracture in the thin skull to enlarge. This interposition of tissue prevents osteoblasts from migrating, inhibiting fracture healing. The resorption of the adjacent bone by the continuous pressure from tissue herniation through the bone gap adds to the progression of the fracture line.

Incidence reported is only .05 to .1% of skull fracture in childhood

They are classified into 3 types:

The type I GSF refers to GSF with a leptomeningeal cyst, which may be seen herniating through the skull defect into the subgaleal space.

In type II lesion there is damaged or gliotic brain .

In type III a porencephalic cyst can be seen.

An increasing order of the defect is associated with an increasing severity of the neurological deficit.

While CT scan can pickup an already established lesion, magnetic resonance imaging has an advantage of detecting dural tear immediately following the head trauma and a timely correction can be helpful in the prevention of growth of the fracture.

The treatment is surgical and consists of reduction of the herniated cerebral tissue and repair of the dural laceration or cranioplasty. A shunt surgery may be performed to decompress the cyst and treat localised dilatation of the ventricles.
Prompt recognition and early diagnosis are essential to prevent the development of neurological complications. Hence, it is essential to follow up cases of head trauma radiologically and clinically until healing occurs.