神経症状を呈した脊柱管内囊腫性病変（juxta-facet cyst）の7例

Spinal Juxta-Facet Cyst : Report of Seven Cases and Review of the Literature

　抄録：椎間関節周囲に生じる囊腫性病変は，滑膜囊腫とガングリオン囊腫に大別されてきたが，最近ではこれらは一括してjuxta-facet cyst（JFC）として扱われている．神経症状を呈したJFC 7例の臨床症状，画像所見，病理所見について検討した．JFCの発生高位はC1/2，C7/T，L3/4，L5/Sが各々1例，L4/5は3例であった．JFCは椎間関節近傍に局在することから，腰椎例のうち4例は神経根症状を，C7/Tの症例はBrown-Sequard型の麻痺を呈した．腰椎変性すべり3例，腰椎変性側弯1例，環軸椎亜脱臼が1例存在し，全例椎間関節のOA変化が認められた．MRIでは，T1強調像で低から等信号，T2強調像で高信号を示し，ガドリニウムで囊腫の辺縁が造影された．C1/2の症例に対してはMagerl法による固定術とMcgraw法による腸骨骨移植のみを行い，それ以外は囊腫摘出術を行った．Lining cellは2例に認められた．JFCの臨床的特徴と発生機序について文献的考察を加え報告する．

　An intraspinal ganglion cyst and a synovial cyst are referred to collectively as a juxta-facet cyst, because they are hardly distinguishable from the standpoint of clinical and the histlogical studies. Seven patients with juxta-facet cyst, 5 men 2 women, were presented in this paper.

　The average age at the time of surgery was 63.9 years old. Juxta-facet cyst was presented at lumbar spine in five patients：3 patients demonstrated at L4/5, 1 patient at L3/4 and L5/S respectively. In the other 2 patients, the cyst was located at C1/2 and C7/T. The juxta-facet cyst had a tendency to locate on either side of spinal canal, thus the most of the patients demonstrated unilateral radiculopathy or Brown-Sequard syndrome. Degenerative changes of the facet joint was observed in all cases, which was accompanied by spondylolisthesis in 3 patients. On magnetic resonance imaging, the cyst was demonstrated in low signal intensity on T1-weighted images and high intensity on T2-weighted images. The margin of the cyst was enhanced with gadolinium-DTPA. Excision of the cyst under laminectomy was done in all patients except for the case with C1/2 cyst who was treated by facet fusion using Magerl's transarticular screw fixation. Histologically, the lining cell was observed in 2 out of 6 cases.

　Clinical findings, histology, and surgical outcome of the juxta-facet cyst were discussed.