Nowadays there is enough evidence that tumors acquire microcirculation not only by angiogenesis. The concept of Vasculogenic Mimicry (VM) by melanoma cells was introduced in 1999 by Maniotis and is the ability of aggressive melanoma cells to form Extracellular Matrix (ECM)-rich vasculogenic-like networks. One form of VM is a histological pattern in tumors detected by Periodic Acid Schiff (PAS)-staining (PAS loops). Another form of VM refers to cancer cells directly lining tumor spaces or channels, which contain erythrocytes (blood lakes). Both forms are a result of dedifferentiation by aggressive melanoma cells adapting an embryonic-like phenotype. Since the first description of Vasculogenic Mimicry (VM) this concept is found in other aggressive tumor.