Tumor Cell Cluster Angiopellosis Extravasation. In vivo imaging of a cluster of injected fluorescently-labelled HeLa cervical cancer cells undergoing extravasation through angiopellosis. The HeLa cell cluster (cyan) is lodged in the lumen of blood vessel (red), prompting vascular remodeling. The HeLa cell cluster is removed from the blood vessel into surrounding tissue as a multicellular group. 3D rendered version on right. SB = 20 μm.