Figure 1

Examples of LVI and BVI in invasive breast cancer sections stained with H&E, D2-40 and Factor VIII. A: H&E conspicuous carcinoma emboli in large and small vascular spaces (single arrows) accompanying structurally identified blood vessels (double arrows). B: similar section stained with D2-40 confirming that these are LVI (arrows). C: carcinoma emboli in small vessels (arrows) that could not be characterised on H&E section. D: similar section stained with D2-40 confirming that these are LVI (arrows). (Scale bar 100 μm). E & G: carcinoma cells within Factor VIII-positive vessels. These are negative for D2-40 (F & H), indicating BVI. (Scale bar 10 μm). I-K show consecutive sections stained with H&E (I) showing tumour cells inside endothelial lining space, however, D2-40 (J) and Factor VIII (K) are both negative suggesting stromal artifact (note positive staining of blood vessel with Factor VIII). L: pattern of D2-40 staining in normal breast duct myoepithelium (single arrows) and how it is different from that of lymphatic endothelium (double arrows). (Scale bar100 μm).