側脳室に多房性嚢腫を形成した乳児奇形腫と考えられた1例

Neonatal Intracranial Tumor Highly Suspected of Teratoma in the Lateral Ventricle Consisting of Multiple Cysts : case report

I．はじめに

　乳児期の脳腫瘍の頻度は全脳腫瘍の1％未満を占めるに過ぎず^3,12），さらにDi Roccoらの国際小児脳神経学会の乳児期脳腫瘍の統計では頭蓋内奇形腫は5％である^2）．また，乳児頭蓋内奇形腫は正中線上に巨大な実質成分の腫瘤を形成するのが特徴であるが，今回われわれは，側脳室内に多房性嚢腫を形成した乳児頭蓋内奇形腫と考えられた1手術例を経験したので報告する．

Neonatal intracranial teratoma is rare and early attempts at surgical treatment are not usually successful.We describe an exceptionally rare case of neonatal intracranial tumor in the lateral ventricle composed ofmultiple cysts with little mass content which was highly suspected of teratoma and treated succesfully bymicrosurgery.

A 55-clay-old male was admitted to our hospital with complaints of convulsive seizure. Examinationfound no obvious neurological deficit except mild enlargement and bulging of anterior fontanel. Therewere no abnormal laboratory findings. Computerized tomography with contrast medium revealed an 8cmmulticystic lesion with little mass content in the right lateral ventricle and hydrocephalus. Magnetic reso-nance imaging showed the cystic content as slightly higher in intensity than CSF on the TI-weighted im-age and of higher intensity than CSF on the T2-weighted image. The cyst wall was enhanced onT1-weighted image with gadolinium. The aqueduct was obstructed by compression due to the in-traventricular cyst. A right occipitoparietal craniotomy was performed, which disclosed a hair in the cystwall, two huge cysts, and independence of the intracystic lesion from the lateral ventricle. The tumor wasremoved except for a small part adjacent to the pineal region, from which the tumor had presumably ori-ginated. Mature teratoma was highly suspected on the basis of the hair in the cyst wall and histological ex-amination of the specimen, which revealed hamartomatous tissues derived from two germ cell layers. Aftersurgery, his hydrocephalus was improved and convulsive seizures were reduced remarkably. He was dis-charged ten clays later and is being followed up. Reoperation will be performed if regrowth of the residualtumor occurs.