PECAM1 and neoplasm: Utilizing the 3D fusion tumor samples, CD31 immunohistochemistry showed three patterns of angiogenesis (Figure 4): pattern A, homogeneous with high vascular density (mean CD31 density: 410 spots, SD: 208) (10% of cases); pattern B, low vascular density (mean CD31: 103 spots, SD: 57) (8% of cases); pattern C, mixed heterogeneous angiogenic signature (82% of cases).