Upstream Effects: Intraoperative Migration of Intradural Extramedullary Tumor After Non–Adjacent Level Stenosis Decompression

Abstract

A 74 year-old man with back pain, foot numbness, and hip/thigh radiculopathy was found to have an L1-2 intradural extramedullary (IDEM) neoplasm and severe L4-5 stenosis. He was taken to surgery for L4-5 minimally-invasive (MIS) laminectomy for decompression and concomitant L1-2 MIS laminectomy for tumor resection. The L4-5 laminectomy was completed first followed by the separate L1-2 laminectomy. Upon extensive intradural exploration at L1-2, no neoplasm was found. Immediate postoperative imaging showed that the IDEM tumor had migrated caudally by nearly a complete spinal level, presumably as a result of changes in cerebrospinal fluid pressure and resultant shift in intradural contents after the L4-5 laminectomy. The patient was taken back to surgery for successful resection of the IDEM, with improvement in his symptoms.