骨化を伴った脊髄髄膜腫の2例

Two cases of ossified spinal meningioma

I．はじめに

　脊髄髄膜腫は，全脊髄腫瘍の中で約25％を占め^6），神経鞘腫に次いで多いものである．一般に髄膜腫が組織学的に多様性を示すのはよく知られた事実であり^6,8），骨化もその組織学的多様性の一つであるが，脊髄に発生する髄膜腫で骨形成を示すものは2-3％と稀であると言われている^2,3）．

　今回われわれは，病理組織学的に骨化型の脊髄髄膜腫であることが確認された症例を2例経験したので，若干の文献的考察を加えて報告する．

It is generally known that meningioma has histolo-gical pleomorphism and ossification is one of them. In the cases of spinal meningioma, osteoblastic type is rare. We encountered two different types of ossified spinal meningioma. Two cases of ossified spinal meningioma are reported in this paper. One case is that of a 45-year-old male who had a sudden transient tetra-paresis with a tumor located in the upper cervical spin-al column. The tetraparesis was caused by the patient's head having been hit. Another case is a 74-year-old female, who had progressive paraparesis and hypesthe-sia in her lower extremities, with a tumor located in the 9th thoracic spinal column. The MRI findings in these cases suggested that an ossified area was included in the tumor. We performed surgical therapy in both cases, and an operative finding was that these tumors had a very hard component. Histopathological diagno-sis in both cases was meningioma. The former included isolated matured bone tissue with fat marrow mixed with the tumor tissue, and the latter included scattered matured lamellar bone tissue. These tumors are consi-dered to be osteoblastic in type.