髄膜腫と聴神経腫瘍が兄弟姉妹に発生した2家系

MENINGIOMA AND ACOUSTIC NEURINOMA OCCURRED IN TWO SIBLINGS OF TWO DIFFERENT FAMILIES

　抄録　脳腫瘍の家族内発生例は，脳腫瘍の遺伝形成や発生機序を解明する上で興味深い資料を提供するものと思われる。著者らは，神経皮膚症候群やfamilial cancer syndromeとの関連をみない，髄膜腫と聴神経腫瘍が兄弟姉妹に発生した2家系4症例を経験した。このような脳腫瘍の家族内発生例は文献上117家系あり，これらのうち病理組織学的に異なる腫瘍の組み合わせは6家系であった。また1970-1979年の日本の脳腫瘍全国集計調査では，家族内発生例56家系のうち16家系が異なる腫瘍の組み合わせであった。いずれの報告例においても，我々の症例のような髄膜腫と聴神経腫瘍（神経鞘腫）の組み合わせは認められなかった。以上，遺伝学的に同等と考えられる同胞間に，中胚葉由来の髄膜腫と外胚葉由来の聴神経腫瘍が発生した2家系4症例について，若干の文献的考察を加え報告する。

The authors reported familial brain tumors in which meningioma and acoustic neurinoma occur-red in two siblings of each two families with no evidence of the neurocutaneous syndromes, nor the familial cancer syndromes.

Case A-1 is a 49-year-old female admitted to the hospital because of bilateral visual disturbance in July of 1976. A suprasellar mass was observed by CT scan. Right frontal craniotomy and removal of the tumor were done in July of 1976. Histolo-gical diagnosis was meningothelimatous meningio-ma. Case A-2 is a 47-year-old female, a younger sister of case A-1. Tinnitus, hearing disturbance, hemifacial sesnsory involvement of right side and impaired gait occurred at the end of 1981. Tomo-graphy revealed the dilatation of the right internal auditory canal. A multicystic mass was observed at the right cerebellopontine angle by CT scan. An operation was performed in May of 1982, and the tumor was diagnosed as Antoni A type neuri-noma.

Case B-1 is 23-year-old male who was admitted to the hospital in April of 1975, following the sudden onset of general convulsion. Left carotid angiogram showed the elevation of middle cerebral arteries and a tumor stain at the left temporal region. An operation was performed to remove the left sylvian tumor in April of 1975, and the tumor was diagnosed as transitional meningioma. Case B-2 is a 32-year-old female, an elder sister of case B-1. Bilateral tinnitus and hearing distur-bance occurred in 1973. She complained left hemi-facial sensory involvement and impaired gait in July of 1979. CT scan showed mass lesions with markedly contrast enhancement effect at the bila-teral cerebellopontine angles. An operation was performed to remove the left tumor in November of 1979 and the right tumor in July of 1980. His-tologically the both tumors were diagnosed as Schwannoma.

The authors have collected reports of 117 fami-lies in which intracranial tumors occurred without evidence of the neurocutaneous syndromes and the familial cancer syndromes. Six out of 117 families showed histologically different kind of tumors, however the combination of meningioma and neu-rinoma could not be found. Consequently our cases of meningioma and neurinoma occurred in two siblings of two different families must be the first report.