第4脳室内pearly tumorの経験—epidermoid 2症例とdermoid 1症例

Three Cases of the Dermoid and Epidermoid Tumors in the 4th Ventricle

Ⅰ．緒言

　頭蓋内pearly tumorはepidermoidとdermoidが一括されていることがある^24）．このうち，epidermoidは，令脳腫瘍の約1％（Gendell^4）ら1976，Granl ＆ Austin^6）1950，桂^10）ら1958，Mahoney^14）1936，Zülch^24）1965）で，dermoidは0.1-0.4％（桂^10）ら1958，Zülch1965）とされている．最近Guidetti ＆ Gagliardi^7）（1977）は4,296例の脳腫瘍症例中31例のepidermoidと21例のdermoidを認めているが，第4脳室内が好発部位の1つにされているepidermoidでも，第4脳室内epidermoid 2例，dermoidが2例報告されているに過ぎない．

　本邦では小脳虫部を含めて第4脳室内のpearly tunlorつまりepidermoid，dermoidの報告は20例に満たず，第4脳室内epidermoid 9例，　dermoid 1例，小脳虫部のepidermoid 4例，dermoid 2例（Table 1）と少ない．

Two cases with epidermoid and one case with dermoid in the 4th ventricle were treated in our clinic during the last one year. The clinical findings in these three cases were described, and dermoid and epidermoid tumors in the 4th ventricle were discussed dealing with the incidence and the characteristic features of the findings in CT scanning. The correct diagnosis of both epidermoid and dermoid in the 9th ventricle was done by CT-scanning which showed an irregular low density area of EMI No. -4~12 in the posterior fossa without any contrast media enhancement.