Vasculogenic Mimicry in Urothelial Carcinoma and Its Association With Clinicopathologic Features

Bladder cancer is the ninth most common cancer worldwide which seriously affects human health. In Egypt, it is the third common malignant tumor.

Urothelial carcinoma (UC) is considered the most common histologic type of bladder cancer.

It is well recognized that the biological behavior of several cancers is closely related to their blood supply. Tumor progression and metastasis have been long associated with tumor angiogenesis. However, several studies demonstrated that vascular targeting drugs which induce endothelial cell apoptosis have a little effect. So, it has been suggested that novel tumor microcirculation patterns may exist in these neoplasms.

Vasculogenic mimicry (VM), is a novel tumor microcirculation system. Maniotis et al initially discovered VM in melanoma and defined these channels to be composed of tumor basement membrane lined externally by tumor cells, lacking blood vessel endothelium and containing plasma and red blood cells. So VM can be distinguished using immunohistochemical (IHC) staining and histochemical double staining. VM is CD31- or CD34-negative (endothelial markers) and periodic acid-Schiff (PAS) positive.

Vasculogenic mimicry was detected in several malignant tumors. Several studies reported that VM can promote tumor progression and metastasis and it is positively associated with pathological grade, stage, recurrence and drug resistance. Previous studies which evaluate, the role of VM in urothelial carcinoma yield controversial results. So, the value of VM in urothelial carcinomas and its relation to the clinicopathologic parameters remains to be elucidated.