Relationship between vasculogenic mimicry and clinical pathological characters in retinoblastoma

Abstract

To explore if vasculogenic mimicry (VM) exists in retinoblastoma (Rb) and to explore the clinical significance of VM. It was an experimental study. Sixty Rb specimens with complete clinical and prognostic data were collected. Periodic acid-Schif staining and immunohistochemical staining of CD34 were conducted to explore if VM exists in those Rb specimens. The expression of HIF-1alpha and VEGF were examined by immunohistochemical staining. The expression of CD34 endothelial antigen was used to label the neo-microvessels. Microvessel density (MVD) in retinoblastoma tissues was calculated. In HE staining slides, VM was present in Rb specimens and was formed by tumor cells but not endothelial cells. Red blood cells were present in the VM. VM existed in 18.33% (11/60) of the Rb specimens. Low R-E graded Rb specimens exhibited a higher VM positive rate than that in the high R-E graded Rb (chi(2) = 8.861, P < 0.05). The positive rate of VM was 4.34% in differentiated type of Rb and was 22.02% in undifferentiated type of Rb (chi(2) = 4.872, P < 0.05). HIF-1alpha and VEGF expressions in Rb with VM were significantly greater than those in Rb without VM (P = 0.001). The density of endothelial vessels correlated with VM. The mean MVD was 49.77 +/- 2.05 in Rb without VM and 36.53 +/- 1.15 in Rb with VM (P < 0.05). VM exists in Rb. Highly differentiated Rb exhibits more VM than that in less differentiated Rb. Expression of HIF-1alpha and VEGF is greater in Rb with VM, indicating that these factors may stimulate the occurrence of VM.