Giant Tarlov Cyst presenting as pelvic mass: Often doing less is better.

Background: Tarlov cysts are sacral perineural cysts arising between the peri and endoneurium of the posterior spinal nerve root at the Dorsal Root Ganglion and have a global prevalence rate of 4.27%. These are primarily asymptomatic (only 1% with symptoms) and typically arise in females between the ages of 50-60. Patients' symptoms include radicular pain, sensory dysesthesias, urinary and/or bowel symptoms, and sexual dysfunction. Non-surgical management with lumbar cerebrospinal fluid drainage and computerized tomography-guided cyst aspiration typically provide only months of improvement before recurring. Surgical treatment includes a laminectomy, cyst, and/or nerve root decompression with fenestration of the cyst and/ or imbrication. Early surgery for large cysts provides the longest symptom-free periods. Case Description: A 30-year-old male presented with a very large magnetic resonance-documented Tarlov cyst (Nabors Type 2) arising from bilateral S2 nerve root sheaths with marked pelvic extension. Although he was initially treated with a S1, S2 laminectomy, closure of the dural defect, and excision/marsupialization of the cyst, he later required placement of a thecoperitoneal shunt (TP shunt). Conclusion: A 30-year-old male with large Nabors Type 2 Tarlov cyst arising from both S2 nerve root sheaths required a S1-S2 laminectomy, dural closure/marsupialization, and imbrication of the cyst, eventually followed by placement of a TP shunt.