Intradural iatrogenic epidermoid cyst at cauda equina: A case report

BACKGROUND: Spinal epidermoid accounts for <1% of all primary spinal cord tumors. They occur due to the invagination of epidermal elements into the neural tube during the embryonic period. Even more infrequent are spinal epidermoid cysts that occur without attendant spinal dysraphism (e.g., as occurs with the iatrogenic inoculation of epithelial cells in the subarachnoid space following a lumbar puncture). CASE DESCRIPTION: A 38-year-old female with a history of epidural spinal blocks at L2-3 for two previous pregnancies presented with low back pain, right lower extremity weakness (4/5 level), hyporeflexia, and tingling/ numbness in the right L3-5 distribution. The lumbar MR demonstrated an intradural extramedullary lesion at the L2-L3 level that compressed the cauda equina/nerve roots. MR findings were compatible with an epidermoid cyst, this was histologically confirmed following a microsurgical L2-3 laminectomy for lesion resection. Pathologically, the lesion demonstrated a keratinized stratified squamous epithelium with keratin content without cutaneous attachments, thus confirming the diagnosis of an epidermoid cyst. Postoperatively, her sensory complains improved and her motor strength fully recovered to the 5/5 level. CONCLUSION: Patients with spinal epidermoid cysts typically present with underlying spinal dysraphism, but only rarely do iatrogenic cases arise. Here, we presented a patient who developed a spinal lumbar epidermoid cyst in a female patient after undergoing spinal epidural anesthesia during pregnancy. Notably, this was successfully treated a with decompressive laminectomy and microsurgical resection.