頭皮下から硬膜下に及ぶ頭蓋内炎症性肉芽腫の1例

A Case of Intracranial Infectious Granuloma Extending into Subcutaneous and Subdural Space

Ⅰ．はじめに

　頭蓋内感染性疾患のなかでも硬膜下膿瘍自体が頭蓋内膿瘍の20～25％と比較的稀であり，しかも大半は膿瘍壁に囲まれた腔内に膿汁が貯留した形状をとっている⁵⁾．最近われわれは，感染により形成された炎症性肉芽腫が硬膜下腔から頭蓋骨を破壊して頭皮下に進展していた1例を経験した．類似した形状，進展を呈する炎症性肉芽腫は極めて稀であったので，若干の文献的考察を加え報告する．

A case of intracranial infectious granuloma extending into subcutaneous and subdural space mimicking malignant bone tumor was reported. A 49-year-old male was admitted tour service with complaint of left frontal subcutaneous and bone tumor. Neurological examination demonstrated mild disorientation only except for pre-existeng Schizophrenia. CT scan and Gadolinium-enhanced MRI revealed left frontal intraosseous and subdural mass accompanied with remarkable edema. Left frontal bone was destructed by this mass. However,inflammatory sign nor malignant tumor could be observed and left frontal craniotomy and removal of the tumor was performed. The tumor was solid,elastic hard and existing from intra-osseous,epidural and subdural space compressing the cortex. No abscesss cavity could be found. Histological examination revealed infectious granuloma accompanied by remarkable neutrophil infiltration only. The patient showed good post-operative course,and returned to previous condition,pre-existeng Schizophrenia only.

　Intracranial infectious granuloma extending into subcutaneous and subdural space destructing the bone was rare condition. From literature,similar cases could be found in granuloma arising from osteomyelitis. In this case,destructed bone beneath the epi- and subdural tumor support this route of infection.