1004 - The combination of a perineural cyst and epidural lipomatosis at the same level: a case report

Case Diagnosis: epidural lipomatosis and perineural cyst at L5-S1.

Case Description: A 51-year-old male presented with chronic low back pain and right L5 radiculopathy. His symptoms included numbness and pain along the right lower limb on L5 distribution. Despite a trial of conservative measures such as physical therapy and NSAIDs, his symptoms persisted. Physical exam revealed positive straight leg raise and slump sit tests, which reproduced radicular pain in the right lower extremity. Neurological exam did not show any signs of upper motor neuron involvement. MRI of the lumbar spine demonstrated epidural lipomatosis at the L4-5 and L5-S1 levels, along with a perineural cyst at L5-S1, which was causing severe central spinal stenosis. Initially, he underwent right L5-S1 transforaminal epidural injection (TFEI) and S1 TFEI, which provided some functional improvement in terms of standing and walking ability but did not alleviate pain. Subsequently, underwent L5-S1 interlaminar epidural steroid injection and L5-S1 facet joints injection.

Discussions: This case highlights the complexity of managing lumbar spinal stenosis, especially when complicated by epidural lipomatosis and perineural cysts at the same level. Despite initial attempts with transforaminal epidural injections, the patient's symptoms persisted, necessitating a different approach including interlaminar epidural and Z-joint steroid injections were employed to target the severely narrowed canal and perineural cyst. Long-term follow-up is necessary to monitor the patient's progress and consider additional treatment options if needed.

Conclusions: Interventional pain management techniques, such as epidural steroid injections and Z-joint injections, may be effective in managing lumbar spinal stenosis and radiculopathy in select patients with epidural lipomatosis and perineural cysts at the same level.