Search

Pineal parenchymal cell tumors (PPCTs) with or without metastasis into the lumbar region by way of the cerebrospinal fluid were treated successfully with combination chemotherapy using cisplatin, vinblastin, and bleomycin (PVB) or cisplatin and vinblastin (PV) and low-dose irradiation (25 approximately 30 Gy). Our series included a case of pineoblastoma, two cases of mixed pinocytoma/pineoblastoma, and a case of pineocytoma, compared to which the data held by the All Japan Brain Tumor Registry (AJBTR) included information on 47 cases pineocytoma and 20 of pineoblastoma. All our patients have survived, with scores of 90% or over on Karnofsky's performance scale, for 2-12 years of follow-up so far; however, the 5-year survival rates of the patients recorded by AJBTR were 83% for pineocytoma treated with radiation and 43% without radiation; and 42% for pineoblastoma treated with radiation and 50% without radiation. Incomplete or varied chemotherapeutic regimens used in different medical centers to treat PPCTs precluded an evaluation such as was made by AJBTR. Our results suggested that combination chemotherapy with low-dose back-up radiotherapy may be the treatment of choice for primary or recurrent disease with or without dissemination in PPCTs.

Venous malformations in the posterior fossa are relatively rare. Although the introduction of CT and MRI has made them easier to detect, their treatment is still controversial. Based on our experience with six patients and a review of the literature, we have tried to establish guidelines for their treatment. Since they have a benign natural course and may provide venous drainage in the posterior fossa, venous malformation found incidentally, unruptured venous malformation with nonhaemorrhagic complications, and those accompanied by small intracerebellar haematoma of less than 2 cm in diameter due to their rupture, should be treated conservatively unless they are associated with a coexistent malformation. Venous malformation with intracerebellar haematoma larger than 3 cm or reexpansion of the haematoma due to rebleeding should be treated surgically by evacuation of the haematoma. Resection of venous malformations in the posterior fossa should be restricted to cases in which the malformation is small and does not serve as a functional venous drainage route. Radiation therapy, including the "gamma-knife", may be a treatment of choice in the future.

Arachnoid cysts are found wherever the arachnoid membrane exists. Therefore, arachnoid cysts tend to occur extracerebrally. A case of an intraventricular arachnoid cyst in a 37-year-old female is reported. The cyst was found in the left lateral ventricle and arose from the choroid plexus. The cyst wall, histologically, consisted of the arachnoid cell lining. Light microscope examination showed the hypocellular membrane without glial tissue. Electron microscope examination showed that the cyst lining cells adhered by an interdigitation with desmosome and the cells had no microvilli. These findings were compatible with the features of an arachnoid cyst.