腫瘍内出血を来した大孔髄膜腫の1例

Intratumoral Hemorrhage Caused by Foramen Magnum Meningioma: A Case Report

Ⅰ．はじめに

　脳腫瘍による頭蓋内出血は，転移性脳腫瘍や神経膠芽腫などの悪性脳腫瘍では日常的に経験されるが，良性腫瘍である髄膜腫においては比較的少なく¹¹⁾，その機序も不明な部分が多い．今回われわれは，経過中に腫瘍出血を来した大孔髄膜腫の1例を経験したので文献的考察を加えて報告する．

　Intratumoral bleeding from a meningioma is very rare. We herein report a case of a foramen magnum meningioma which presented in association with intratumoral bleeding.

　A 49-year-old female who had been suffering from occipital headache and shoulder pain on neck motion was referred to our hospital to undergo treatment for a tumor located in the posterior fossa. Magnetic resonance imaging (MRI) demonstrated a foramen magnum meningioma which originated at the lower clivus and extended to the C2 level of the vertebral column. Marked compression and distortion of the medulla oblongata and spinal cord was also noted. Surgery was therefore planned. The patient thereafter suffered from a sudden onset of headache, vomiting and hoarseness, and was transferred to our hospital. A computed tomography (CT) showed intratumoral bleeding, which extended to the subarachnoid space and the fourth ventricle. The tumor, as well as the massive hematoma, were both immediately removed. The histological diagnosis was meningothelial meningioma.

　We also reviewed the pertinent literature and propose the possible mechanism for such tumor bleeding in this particular location in which the blockage of the cerebrospinal fluid caused a craniovertebral pressure gradient, which thus resulted in intratumoral bleeding.