頭蓋内進展を伴う第2頚神経鞘腫の1例

C2 Neurinoma with Intracranial Extension: A Case Report

Ⅰ．はじめに

　大孔部腫瘍は，その局在を示唆する神経学的所見に乏しく，診断が容易でない．今回われわれは，著明な頭蓋内進展を来し，大孔症候群を呈して認められた第2頚神経鞘腫を経験した．本腫瘍は脊柱管内外，硬膜内外に広がり砂時計腫となっている一方，硬膜内腫瘍は大孔を越えて斜台部へ進展．同部に巨大腫瘍を形成し，脳幹および上位頚髄を高度に圧排していた．この特異な進展様式のみられた頚神経鞘腫について，文献的考察を加え報告する．

　We report a rare case presenting with a C2 neurinoma,which extended beyond the foramen magnum,producing a huge mass at the clivus. A 10-year-old boy with medical history of glycogenosis type Ⅷ and attention-deficit hyperactivity disorder had been suffering from progressing foramen magnum syndrome for 36 months. MRI demonstrated a huge tumor,70mm in a diameter,which distributed in both the intra- and extra-spinal canal at the C2 level and extended into the intracranial space beyond the foramen magnum. The tumor was totally removed via the trascondylar fossa approach with C1 hemilaminectomy. Operative findings indicated that the tumor arising from extradural C2 nerve intruded into the intradural space,and extended beyond the foramen magnum. Foramen magnum tumors sometimes remain unrecognized until severe neurological deficits develop because of bizarre symptomatology. Surgical strategies with less invasiveness based on early diagnosis lead to successful recovery of neurological function.