Vasculogenic mimicry (VM) has been observed in melanoma and in some nonmelanomatumor types. It is unknown whether a similar VM phenomenon exists in astrocytoma.The present study was to examine 45 astrocytomas (including World Health Organizationgrade II 15 cases, grade III 15 cases, and grade IV 15 cases) by CD34 endothelialmarker periodic acid–Schiff (PAS) dual staining to see if VM existing in these tumors. Theresults demonstrated that endothelium-lined vessels dominated the tumor microvasculatureand stained positively for PAS, laminin, and endothelial marker. PAS-positive patternof VM was found in two grade IV astrocytomas. Channels stained positively for PAS, laminin,and negatively for CD34 of the VM entrapped in the tumor tissue. Erythrocytes couldbe observed in some of these channels. In these networks of PAS-positive pattern, spots ofweak reaction for CD34 were observed, suggesting the incorporation of VM channel andnormal vessel. Furthermore, in astrocytoma, especially glioblastoma, focus of anaplastic tumorcells appeared with CD34 expression, whereas some tumor cells lost glial fibrillary acidprotein expression. It is assumed that genetically deregulated tumor cells in astrocytomacould lose the astrocyte-specific protein and express inappropriate markers not expected incells of astrocyte lineage. The present results suggest that VM phenomenon exists in somemalignant astrocytoma.