乳児髄膜腫—その1例と文献例の検討

INTRACRANIAL MENINGIOMA IN A FIVE-MONTH-OLD INFANT : A CASE REPORT AND REVIEW OF THE LITERATURE

いとぐち

　乳幼児脳腫瘍は，従来きわめて稀であるとされていたが，近年の小児における神経学的診断技術の進歩によつて最近では漸次症例が増し，またその手術成績も向上してきている。

　しかし乳幼児脳腫瘍においては成人脳腫瘍に比して神経膠腫が圧倒的に多く，髄膜腫，下垂体腫瘍，神経鞘腫はきわめて少ない。

In the pediatric neurosurgery the meningioma is considered to be a tumor of unusual occurrence, In infant younger the age of two years, only 21 cases have been reported in the liturature. The authors reported such a case because of its rarity and illustrated certain important points from the analysis of 17 cases (including presented case) in the liturature.

The presented case is a five-month-old baby. He had apparently been well until about five weeks ago when he developed myoclonic convulsion. In spite of administration of anticonvulsants the con-vulsions did not been controlled. One month after occurred he admitted the Department of Neuro-logical Surgery, Sapporo Medical college and Hospi-tal complaining of convulsions, abnormal enlarge-ment of skull, right hemiparesis and lethargy. On admission, He lay in a stuporous condition, re-sponding only pain stimuli. The circumference of the head was 48.9 cm and anterior fontanelle was tense. There was positive Macewen's sign and mild weakness on the right side. Undergeneral anesthesia tumor in the left frontotemporoparietalwas removed en bloc. There was an encapsulated xanthochromic collection of fluid around the tumor and tumor has no attachment to the dura. The postoperative course was uneventful and the baby was made a complete recovery. At present (2 years and half after operation) he is without neurological deficit.

A review of the liturature revealed several un-usual features of intracranial meningioma in infant.

1. Infant meningioma is fairly rare. In the combined series of 215 cases of intracranial tumors during the first two years of life, only 9 were meningiomas, the incidence being 4.2%.

2. Symptoms in these cases had been present from one day to 18 months before admission, the average being 4 months. Though meningioma is one of benign tumors, its clinical course was very rapid as similar as glioma. Rapid increase in the cir-cumference of the skull, asymmetry of the skullexpansion and accessory signs of increased intra-cranial pressure demand particular attension in the diagnosis.

3. Analysis of anatomic locations of these 17 cases revealed that the cerebral convexity consti-tuted 82.3% and tumors were not adherent to dura in the majority of the cases.

4. In adult, meningioma with cyst is fairly rare but in infant its incidence was 29.4%.

5. It is felt by many that meningioma occurring in those younger ages are most prone to sarco-matous behavior and thus are attend by a poor prognosis by comparision with adult. But in these 17 cases about after 1961, there was no parative death. But in these 17 cases about 59% was the benign meningioma and in 9 cases who had been operated after 1961 there was no operative death.