Intraosseous pseudomeningocele of the mobile spine: a case report and review of the literature

Emily Rider-Longmaid, Junjian Huang, Ronnie Sebro, Harvey Smith

Pseudomeningoceles most commonly occur due to prior trauma or surgery and are often located in the posterior paraspinous tissues. Here, we report a case of an intraosseous pseudomeningocele that mimicked an intra-osseous T2 hyperintense lesion in the L1 vertebral body. A 64-year-old male presented with back, left lateral thigh and left knee pain lasting several months. He had no prior history of trauma or surgery. Radiographs of the lumbar spine showed mild levoscoliotic curvature of the lumbar spine, Baastrup's changes between the spinous processes, multilevel degenerative disc disease and facet arthropathy. Magnetic resonance imaging (MRI) of the lumbar spine performed without intravenous contrast showed severe spinal canal stenosis from L1-L2 to L3-L4 and moderate spinal canal stenosis at L4-L5. MRI also showed a 2.5-cm T2 hyperintense lesion involving the posterior aspect of the L1 vertebral body, with questionable contiguity with cerebrospinal fluid. Computed tomography (CT) myelogram was performed instead of biopsy. CT myelogram showed contiguity of the lesion with the intrathecal contrast and a rent in the posterior longitudinal ligament and anterior dura consistent with an intraosseous pseudomeningocele. The patient opted for non-operative management of the pseudomeningocele and his lumbar stenosis due to medical comorbidities. This case illustrates a rare case of an intra-osseous pseudomeningocele and highlights the importance of CT myelogram for diagnosis.