[Quantification and morphometric analysis of vascular structures in the bone marrow. A critical review]

The important role of angiogenesis for invasion, tumor growth, metastasis and progression of solid tumors is well established. Only recently, the clinical significance of neovascularization in hematological neoplasms has come into the focus of scientific efforts. Emerging data from these studies suggest that the vascular architecture exerts a pivotal role in acute leukemias and multiple myeloma as well as myeloproliferative disorders. Thus, angiogenesis seems to maintain a general condition for malignant growth and the progression of hematological diseases. However, a major shortcoming is that most of the previous studies include only a simple quantitative evaluation of the microvessel density, and applied methods which were developed primarily for the characterization of angiogenesis in solid tumors. In this context it should not be overlooked that solid neoplasms and the bone marrow reveal significant differences regarding the vascular structures and the distribution of microvessels. Therefore, the usually applied, so-called hot-spot techniques, should be amended by an appropriate and more elaborate computer-assisted morphometric analysis of the microvessel structures. This additional spectrum of information regarding quantity and quality of angiogenesis, enables a further understanding of the morphological changes in the course of diseases, and in particular the effect of various therapies on bone marrow vascularization.