wachsende Schädelfraktur

Leptomeningeal cysts, also known as growing skull fractures, are an enlarging skull fracture that occurs near post-traumatic encephalomalacia. The term cyst is actually a misnomer, as it is not a cyst, but an extension of the encephalomalacia. Hence, it is usually seen a few months post-trauma.

Epidemiology

The majority occur in children <3 years. They complicate ~1% of skull fractures .

Clinical presentation

Children can present with :

• enlarging scalp mass
• seizures
• focal neurological deficit
• headache

Pathology

The exact pathogenesis remains unclear  but it is thought they occur secondary to skull fractures causing dural tears allowing the leptomeninges and/or cerebral parenchyma to herniate into it . Pulsations from CSF erode the fracture margin, resulting in eventual expansion and non-union .

Radiographic features

Plain radiograph

• round or oval lucency with smooth margins

CT

CT scan is the modality of choice for the evaluation of leptomeningeal cyst. It consists of a lytic calvarial lesion with scalloped edges, in which encephalomalacia invaginates. The following features may also be present :

• extracranial brain herniation
• hydrocephalus
• unilateral ventricular dilatation
• porencephalic cyst 

Differential diagnosis

• eosinophilic granuloma
• calvarial metastases
• epidermoid cyst
• osteomyelitis
• congenital calvarial defect

Siehe auch:

• Knochenmetastasen des Schädels
• Schädelfraktur
• intraossäre Epidermoidzyste
• eosinophiles Granulom des Schädels
• Osteomyelitis des Schädels
• kongenitaler Kalottendefekt