PECAM1 and neoplasm: Immunohistochemical analysis revealed tumour cells positive for cytokeratin (CK) (+++), CK5/6 (+++), P40 (+) (Figure 5), epithelial membrane antigen (weak +), cluster of differentiation (CD) 1a (-), factor VIII (-), S100 (-), CD68 (KP1) (-), CD21 (-), CD23 (-), CD31 (-), CD34 (-), leukocyte common antigen (-), vimentin (-), and Epstein-Barr virus-encoded ribonucleic acid/in situ hybridisation (EBER/ISH) (+) (Figure 6).