Fig. 3From: Fast growing angiosarcoma of the right atrium after radiofrequency catheter ablation: a missed diagnosis or misdiagnosis case reportPathological analysis identified the tumor as a primary cardiac angiosarcoma. a Malignant cells are frankly atypical with hyperchromatic nuclei (arrow). They line poorly formed immature vessels containing red blood cells (H&E stain). b Immunohistochemical stain for CD31 (blue) revealed the endothelial nature of the tumor cells (original magnification × 200)Back to article page