leptomeningeal cyst

Wachsende

Schädelfraktur: Die Fraktur der Kalotte war primär nur schmal, fissural (linkes Bild, frische Fraktur, Alter 6 Monate). Im Verlauf weitet sich der Frakturspalt deutlich (rechtes Bild, Alter 14 Monate). Pathogenetisch geht man von einer Mitverletzung der Dura mit Verlagerung von Anteilen derselben in den Frakturspalt aus. Dadurch wird die ossäre Überbauung verhindert und durch den positiven Druck von innen der Spalt eben sogar erweitert. Es besteht in der Folge die Gefahr einer Meningozele oder Enzephalozele.

Wikipedia • CC BY-SA 4.0

Leptomeningeal

cyst • Growing skull fracture - Ganzer Fall bei Radiopaedia

Pathak, S. Growing skull fracture. Case study, Radiopaedia.org. (accessed on 04 Nov 2022) https://doi.org/10.53347/rID-12998 • CC by-nc-sa 3.0 (modified)

Leptomeningeal

cyst • Growing skull fracture - Ganzer Fall bei Radiopaedia

Ibrahim, D. Growing skull fracture. Case study, Radiopaedia.org. (accessed on 04 Nov 2022) https://doi.org/10.53347/rID-53470 • CC by-nc-sa 3.0 (modified)

Leptomeningeal

cyst • Growing fracture of skull - Ganzer Fall bei Radiopaedia

Batta, N. Growing fracture of skull. Case study, Radiopaedia.org. (accessed on 04 Nov 2022) https://doi.org/10.53347/rID-38719 • CC by-nc-sa 3.0 (modified)

Leptomeningeal

cyst • Growing skull fracture - Ganzer Fall bei Radiopaedia

Ibrahim, D. Growing skull fracture. Case study, Radiopaedia.org. (accessed on 04 Nov 2022) https://doi.org/10.53347/rID-64378 • CC by-nc-sa 3.0 (modified)

Leptomeningeal

cyst • Leptomeningeal cyst - Ganzer Fall bei Radiopaedia

Haghighi, S. Leptomeningeal cyst. Case study, Radiopaedia.org. (accessed on 04 Nov 2022) https://doi.org/10.53347/rID-84661 • CC by-nc-sa 3.0 (modified)

Leptomeningeal

cyst • Leptomeningeal cyst - Ganzer Fall bei Radiopaedia

Ayodele, A. Leptomeningeal cyst. Case study, Radiopaedia.org. (accessed on 04 Nov 2022) https://doi.org/10.53347/rID-88781 • CC by-nc-sa 3.0 (modified)

Leptomeningeal

cyst • Growing skull fracture - Ganzer Fall bei Radiopaedia

Ibrahim, D. Growing skull fracture. Case study, Radiopaedia.org. (accessed on 04 Nov 2022) https://doi.org/10.53347/rID-149549 • CC by-nc-sa 3.0 (modified)

Infant who

has been abused. Initial lateral radiograph of the skull (above) shows a stellate skull fracture in the parietal bone. Some of the skull fragments are also diastatic, or spread apart. Followup lateral radiograph of the skull obtained 3 weeks later (below) shows a widening distance between several of the skull fragments.The diagnosis was growing skull fracture, also known as a leptomeningeal cyst.

pediatricimaging.org • CC-by-nc-sa 4.0

Radiopaedia • CC-by-nc-sa 3.0 • de

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 :