[A survey of malignant gliomas accompanied with visceral malignancies]

From January 1984 to December 1997, a total of six patients with malignant gliomas accompanied with visceral malignancies were treated in our department. We reviewed their radiological findings and clinical course. They consisted of four patients with glioblastoma and two patients with anaplastic astrocytoma. Classified according to visceral malignancies, three cases had colon cancer and the rest consisted of thyroid, uterus and prostate cancers. In radiological examinations of the brain (CT scans and MR images), these gliomas were relatively well-circumscribed, as if they were metastatic brain tumors. Of all these six cases, two cases survived more than five years and there were two cases in which there was recurrence within a year. Particularly, in four cases, whose gliomas developed after the treatment for visceral malignancies, two cases survived long-term (more than five years) and there was recurrence in only one case. We speculated that visceral malignancies could affect the nature of glioma progression. Thinking about its mechanisms, we hypothesized as follows; (1) visceral malignancies may activate non-specific, or common antitumor, immunity. (2) visceral malignancies may produce some factors which could affect the biological nature of gliomas. (3) glioma accompanied with visceral malignancy may have genetic uniqueness. Although the cases were limited in number, the present study may be helpful in designing the treatment for such cases and in elucidating the invasive nature of gliomas.