Isolated true anterior meningocele

Chest radiograph of 15 year old male showing mediastinal based large well defined mass lesion in the right upper hemithorax with defect in the vertebral body.

CT scan showing ventral defect in the vertebral body with herniation of meninges which is extending in to right hemithorax and displacing the trachea.

A spinal meningocele is a herniation of the meninges through a foramina or a defect in the vertebral column and is frequently located posteriorly in the lumbosacral area. 

An anterior spinal meningocele is rare and is generally described in the thoracic or sacral region. These frequently occur as a manifestation of generalized mesenchymal dysplasia such as neurofibromatosis type 1 (NF-1) or Marfan syndrome and rarely as an isolated defect.

CT and MR imaging are essential, not only for the diagnosis, but also for the depiction of its relationships to surrounding structures and the exclusion of other possible accompanying lesion such as neuroma in the setting of NF-1.