Fig. 3
From: Pulmonary carcinoma with metastasis in a long-finned pilot whale (Globicephala melas)
Histochemical and immunohistochemical (IHC) characteristics of vasculogenic mimicry (VM) and Epithelial-to-mesenchymal transition (EMT). a Masson’s Trichrome stain reveals a thin layer of stroma sustaining intratumoral capillaries (arrow), whereas VM-figures lack this support (Masson’s Trichrome, 60x). b The same can be visualized with the Periodic Acid-Schiff (PAS) stain, in which the basal membrane of the vessels stains PAS positive (arrow), but do not in VM-figures (PAS staining, 60x). c Intracytoplasmic labelling for pancytokeratin in cells forming VM, confirming their epithelial origin (AE1/AE3 IHC, 40x). d Intratumoral vascular endothelium consistently express vimentin (inset), whereas VM-figures do not (Vimentin IHC, 60x). e A multinucleated neoplastic epithelial cell displayed intracytoplasmic immunolabelling for vimentin (arrow head), feature typical of EMT. Note the staining of the vascular endothelium (arrow) functioning as internal positive control. (Vimentin IHC, 40x)