Diagnosis and treatment of pineal tumours. Kyoto University experience (1941-1984).

Our current policy for the treatment of pineal tumours is presented, based upon our experience of 139 cases of pineal tumours in a period of 44 years from 1941 through 1984. First of all, it should be emphasized that germinomas are extremely radiosensitive and are treated successfully by radiotherapy alone. Accordingly, the treatment of choice for germinomas would be radiotherapy without surgery, if the diagnosis could be made confidently by the modern armamentarium of investigations, including CT, cerebrospinal fluid cytology and serum level of tumour markers, such as alphafetoprotein and human chorionic gonadotropin. When the diagnosis of germinoma is suspected although not straightforward, CT is reexamined after a trial of diagnostic radiation of 20 Gy. If the tumour size has not been reduced at all, it is unlikely that the tumour is a germinoma and surgery should be considered for removal as well as establishment of the histological diagnosis.

Pineocytoma with neuronal differentiation demonstrated immunocytochemically. A case report.

Stereotactic biopsies were obtained from a tumor in the pineal gland of a 37 year old man. Histological and smear preparations were studied using conventional staining techniques as well as immunocytochemical methods with monoclonal antibodies to glial fibrillary acidic protein (GFAP), the neurofilament proteins (NFP), the presynaptic vesicle protein synaptophysin as well as with antisera to neuronal specific enolase (NSE). The tumor was classified as a pineocytoma. The tumor cells uniformly contained no cytoplasmic GFAP but NFP, NSE and synaptophysin as shown by the immunocytochemical techniques. The pineocytoma could thus be subclassified as a pineocytoma with neuronal differentiation. The patient subsequently succumbed due to a hemorrhage into the tumor and autopsy confirmed the biopsy findings. We conclude that immunocytochemical techniques may prove invaluable in the subclassification of tumors of the pineal region.

An immunohistochemical study of intracranial germ cell tumours.

Histologically verified intracranial tumours, mainly germ cell tumours of the pineal and suprasellar regions, were studied immunohistochemically using anti-serum of alpha fetoprotein (AFP), human chorionic gonadotropin (HCG), carcinoembryonic antigen (CEA), human placental lactogen (HPL), pregnancy specific beta-1 glycoprotein (SP-1), glial fibrillary acidic protein (GFAP), S-100 and neuron specific enolase (NSE). In germinomas, HCG positive cells were occasionally demonstrated in cells presenting as syncytiotrophoblastic giant cells (STGC), and GFAP and S-100 positive cells were found in the surrounding gliotic lesions. Teratomas were positive for CEA in their epithelial components. Endodermal sinus tumours were positive for AFP, choriocarcinomas for HCG and SP-1, and embryonal carcinomas for AFP, HCG and SP-1. HCG and SP-1 positive cells were demonstrated in STGC. As for the relationship between serum AFP level and tissue localization, many cases presenting a serum AFP level exceeding 220 ng/ml were positive for AFP in tumour tissue.

Immunohistochemical study of placental alkaline phosphatase in primary intracranial germ-cell tumors.

Indirect immunoperoxidase staining by the peroxidase-antiperoxidase (PAP) technique was carried out on 23 human primary intracranial germ-cell tumors (17 germinomas, one embryonal carcinoma, one yolk-sac tumor, three teratomas, and one teratoma with embryonal carcinoma) and on six human primary pineal non-germ-cell tumors (one pineocytoma, two pineoblastomas, two astrocytomas, and one glioblastoma multiforme). The technique used specific rabbit antisera against placental alkaline phosphatase (PLAP), alpha-fetoprotein (AFP), and human chorionic gonadotropin (HCG). Thirteen of 17 intracranial germinomas (76.5%) showed positive staining for PLAP mainly on the tumor cell membrane. In six primary intracranial non-seminomatous germ-cell tumors, there was weak positive staining indicating the presence of PLAP in only a few cells of one embryonal carcinoma, and in some glandular epithelial cells of one teratoma; this staining was limited to the cytoplasm. None of the other six primary pineal non-germ-cell tumors showed any positive PLAP reaction. From these results, PLAP was shown to be very useful in histopathology as a diagnostic tumor marker of intracranial germinoma. Positive AFP staining was seen in several yolk-sac tumor cells and a few embryonal carcinoma cells. However, no intracranial germinomas and non-germ-cell tumors of the pineal region showed positive reaction. As for HCG, only one suprasellar germinoma and one pineal embryonal carcinoma among 29 specimens contained a few positive-staining tumor cells.

Glial fibrillary acidic protein in medulloblastomas and other embryonic CNS tumours of children.

Investigation of GFAP in 50 medulloblastomas showed a few GFAP-positive tumour cells in 5 cases only; 17 tumours were negative, and 28 showed a "pseudopositivity", i.e. GFAP-bearing cells were identified as reactive or degenerating astrocytes, intermingled with tumour elements. A high GFAP content was seen in 2 small-cell gliomas of the cerebellum, whereas 3 pineoblastomas, 2 neuroblastomas of CNS, and one medulloepithelioma were negative. GFAP is a very good method for identificating astrocytes, but does not seem to be reliable for identifying the origin of undifferentiated tumours such as medulloblastomas. In these neoplasms glial differentiation is lacking or extremely rare, GFAP-positivity being mostly an artifact. The investigation of small tumour samples or the positivity of a single cell are inadequate data for a correct evaluation of the findings, especially taking in mind that GFAP of degenerated astrocytes can be phagocytised by cells other than glial (e.g., macrophages, epithelial and meningioma cells). The importance of carefully checking the whole structure of the tumour is stressed, GFAP positivity or negativity being not a sufficient criterion for its nosological classification.

Intracranial germ cell tumor indicating a high level of alpha-fetoprotein (AFP).

An autopsy case of intracranial and extrapineal tumor is reported. The tumor, detected 2 years and 4 months before death, was an ectopic pinealoma (germ cell tumor) and showed elevated serum alpha-fetoprotein (AFP) of 48,000 ng/ml. Histologically, intra- and extracellular PAS-positive hyaline globules were observed in the tumor. The tumor tissues of the paraffin sections revealed a bright positive fluorescence for AFP with indirect immunofluorescence method. Besides, there were generalized metastases in this case.