胸髄硬膜内血管周皮腫の1例

Hemangiopericytoma on the Intradural Thoracic Spinal Cord: A Case Report

Ⅰ．はじめに

　血管周皮腫は，1942年にStout，Murrayにより初めて報告された発生起源の不明な腫瘍である¹⁶⁾．本腫瘍は，血管に富み，急速に増大する特徴があり，中枢神経系に発生した場合では，肺や骨などの頭蓋外への転移も報告されている悪性腫瘍である．頭蓋内原発腫瘍の1％の頻度で発生するが¹⁰⁾，脊椎・脊髄における硬膜内血管周皮腫の報告は少なく，その多くは脊椎を含む硬膜外発生例である^1,2,4,6,11)．われわれは，胸髄硬膜内血管周皮腫の1例を経験したので，これまでの報告例を検討し，その治療上の問題点などを報告する．

　Hemangiopericytoma develops from many organs. In the central nervous system,most tumors arise in the intracranial portion,and tumors originating from the spinal cord are rare. Its clinical course and neurological characteristics have not been disclosed.

　We present a case of a 51-year-old woman with gradually progressing paraparesis. Magnetic resonance (MR) images of the thoracic spine demonstrated an intradural tumor at the 6 and 7 thoracic vertebral body level. The patient underwent total excision of the tumor. The histological diagnosis was hemangiopericytoma. MR images after the operation showed no residual tumor and the patient was followed up without adjuvant therapy. However, 5 years later, the patient complained of back pain and gait disturbance again, and MR images showed a recurrence of the tumor. We resected the tumor under motor evoked potential (MEP) monitoring and removed the extradural part of the tumor, but the part of the tumor which had infiltrated the spinal cord was left due to the lowering of MEP amplitude. The operation resulted in partial resection.

　Spinal intradural hemangiopericytoma is very rare,and only 15 cases including the present case have been reported. This paper will discuss the clinical characteristics and treatment for this tumor.