Clinicopathological study of pleomorphic xanthoastrocytoma: correlation between histological features and prognosis.

The correlation between histopathological characteristics and prognosis was studied in six cases of pleomorphic xanthoastrocytomas (PXA) found in five patients. With regard to the duration from onset to the resection of the tumor, and the postoperative course, three cases had a favorable prognosis, although one case fatally recurred and in another, serial CT showed rapid tumor growth for 3 years. The histological characteristics of the favorable group of PXA comprised remarkable degeneration, low mitotic activity and a low MIB-1 labeling index. In contrast, the characteristics of the latter two cases of PXA rarely showed degeneration, had atypical mitoses, increasing mitotic activity and a higher MIB-1 labeling index, which indicates that the findings of degeneration, atypical mitoses, mitotic activity and MIB-1 labeling index correlate with the biological behavior of PXA. However, with regard to histological appearance and clinical course, PXA are tumors with a wide range of biological behavior.