The significance of angiogenesis and the vascular architecture have been stressed in numerous studies of the structure and biological properties of the tumor vasculature and blood flow (Folkman and D'Amore, 1996; Jain, 1988). The important question as to whether the vascular architecture of an individual tumor is tumor type specific has been controversial. This is due, at least in part, to the methodologies used. Most reports confine themselves to qualitative observations and comparisons of gross vascular patterns in host and tumor, or to blood vessel density, length and diameter measurements, which in turn vary with the staining and counting techniques.

We studied the microvascular architecture of four different tumor cell lines (CaX, CaNT, SaS, HEC- 1B) in order to determine whether there is a characteristic vascular pattern for different tumor types and whether it differs significantly from two normal tissues, muscle and gut.