MRIで砂時計腫様所見を呈した腰椎椎間板ヘルニアの1例

Lumbar Disc Herniation with MRI Shadow Mimicking a Dumbbell Tumor. Case Report

　今回われわれは，MRIで砂時計腫様所見を呈した腰椎椎間板ヘルニアの1例を経験したので報告する．主訴は左下肢痛・下垂足で，術前に砂時計腫を疑い摘出術を施行したが，腫瘤は硬膜管背側から椎間孔内外に及び，L5/S1椎間板の脱出孔と連続性を認め，腰椎椎間板ヘルニアと診断した．病理組織検査でも軟骨終板を含む脱出ヘルニアであった．このような形態を呈した腰椎椎間板ヘルニアは，われわれが渉猟し得た範囲では，他に報告例がない．術後9カ月の現在，左下肢痛・下垂足も改善し，経過良好である．

　We report a case of lumbar disc herniation in which the MRI shadow resembled that of a dumbbell tumor. The patient's chief complaint was left leg pain and dropfoot, and surgery to resect the tumor was performed. Although a dumbbell tumor was suspected preoperatively, during surgery a mass was observed extending from the posterior side of the dural sac to either side of the intervertebral foramen, and it was in continuity with the L5/S1 intervertebral disc. A diagnosis of lumbar disc herniation was made, and pathological examination revealed a dorsally migrated hernia containing a cartilage end plate. No reports of lumbar disc herniation with similar morphology were found in an extensive search of the literature. As of 9 months postoperatively, the left leg pain and dropfoot have improved, and the patient's course has been favorable.