Post-Traumatic Occipital Intradiploic Encephalocele

Brain parenchyma herniation through a disrupted inner table into an enlarged diploic cavity with an intact outer table is described as intradiploic encephalocele. Intradiploic encephaloceles share common morphologic characteristics with expanding skull fractures and intradiploic arachnoid cysts. Herein, we describe a case of traumatic occipital intradiploic encephalocele.

Cranial computed tomography of an 11-year-old boy revealed erosion of the inner table of the left side of occipital bone and expansion of the cranial diploë by a soft-tissue density with a gyral pattern. His medical history was positive for head trauma at the age of 3 years to the same region. Magnetic resonance imaging showed herniation of left occipital parenchyma with cystic encephalomalacic changes into the diploë.

Intradiploic encephaloceles have different features compared with the classic encephalocele and can be considered as a variant of expanding skull fracture and intradiploic arachnoid cyst.