摘要：

The authors' attitudes toward the diagnosis and treatment of pineal tumors have been dramatically changed in recent years by several important factors : (1) Histological classification has been well established by introduction of the concept of germ cell tumors including germinomas and a variety of teratomas. (2) The value of radiotherapy for germinomas has been firmly established. (3) Operative procedures have been refined by introduction of microsurgical techniques. (4) Preoperative diagnosis has been made easier and more accurate by development of CT and better techniques of cerebrospinal fluid (CSF) cytology, and by the discovery of tumor cell markers such as alphafetoprotein (AFP) and human chorionic gonadotrophin (HCG). One hundred and thirty-four cases of pineal tumors were experienced in the Department over a period of 38 years from 1941 through 1979, which corresponded to 4.9% of all intracranial tumors treated in the same period. There were 82 cases of germinomas (28 histologically verified and 54 histologically non-verified), 23 teratomas, seven pineoblastomas and 22 others. Among the 82 germinoma cases, there were 71 males and 11 females, with a marked male preponderance. A male preponderance was also found for teratomas. It is well known that germinomas are extremely radiosensitive and some of them are radiocurable. The 5-year survival rate of 35 cases of pineal germinomas treated by radiotherapy was 73% and the 10-year survival was 60%, as compared to 9.0% and 5.0%, respectively, in 22 cases of pineal germinomas without radiotherapy. In the cases of teratomas, however, radiotherapy was not effective and the general prognosis was poorer than in germinomas. Surgery is still the treatment of choice in teratomas and occasionally, long-term survival was obtained after total removal of well differentiated teratomas. Recent experience with CT has shown us that all six cases of intracranial germinomas had disappeared by the time 2,000 rad had been given. In CT, the germinoma usually appears as a mass of normodensity or moderately high density which is homogenously enhanced in contrast studies. The border of the tumor is slightly ill-defined and sometimes extends along the ventricular walls. The teratoma usually appears heterogenous with areas of low density, suggestive of cyst formation. However, it is not always possible to differentiate between germinomas and teratomas by CT findings alone. In angiography, hypervascularity is one of the characteristics of malignant varieties of teratomas, such as embryonal carcinomas, yolk sac tumors and choriocarcinomas. In the case of germinomas, tumor cells tend to exfoliate into the CSF. We observed abnormal cells in preoperative CSF in 62.1%of the cases of germinoma, whereas CSF cytology was always negative in teratomas. Therefore, CSF cytology is one of the useful diagnostic tests for pineal tumors. Increased serum level of AFP was observed in six out of seven cases of malignant varieties of teratoma but in none of the 14 cases of germinoma. On the other hand, serum HCG was increased in three out of six teraromas with increased AFP and in seven out of 14 germinomas. Serial determination of these tumor markers was found to be useful in evaluating the effect of treatment and in predicting the prognosis. Our current policy in the treatment of pineal tumors is as follows: l) Ventriculoperitoneal shunting operations should be first performed in the presence of increased intracranialpressure. 2) Efforts for differential diagnosis should be made by CT, angiography, CSF cytology and measurement of AFP and HCG in the serum and CSF. 3) If a germinoma is strongly suspected, a course of radiotherapy for the whole cerebrospinal axis should be given, provided it is tolerated. 4) If a germinoma is suspected but the possibility of other tumors, particularly teratomas, can not be completely excluded, CT is performed again after 2,000 rad of radiation. If there is no reduction in tumor size at all

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