link
Bookmarks
Tumor Vascularity
Andrej Lyshchik, MD, PhD
To access 4,300 diagnoses written by the world's leading experts in radiology, please log in or subscribe.Log inSubscribe
0
0
11
0

KEY FACTS

  • Terminology

    • Imaging

      TERMINOLOGY

      • Tumor Angiogenesis

        • Tumor development requires adequate system of blood vessels supplying adequate nutrition and removal of waste products
        • At earliest stages of neoangiogenesis, tumors recruit vessels from host, most of which come from venous capillary network in form of vascular sinusoids
        • At same time, tumors produce variety of endothelial growth factors, which initiate new tumor development within tumor and surrounding areas
        • At early stages, tumors have hypervascular periphery with hyperemic rim of tissue
        • As tumors progress, central areas may become ischemic due to inability to develop adequate vascular networks
        • Later, ischemic central areas may undergo necrosis
      • Tumor Vessel Morphology

        • Tumor vascular networks usually demonstrate abnormal branching patterns without typical hierarchical order of blood vessel branching seen in normal tissues
        • Tumor neovascularity can also be differentiated from normal tissues by irregular sizes of vessels and presence of arteriovenous shunts
        • On more microscopic level, tumor blood vessels are characterized by paucity of smooth muscle within vessel walls, making them more pliable and less pressure resistant
        • Morphologic appearance of tumor vessels may not allow direct assessment of function of tumor microcirculation or differentiation of benign from malignant tumors due to 20-80% of vascular network being perfused within any given tumor at particular time, while large portions of tumor vascular bed remain dormant
        • This leads to significant variations in tumor blood flow velocities and tumor vascularity between different areas within same tumor
      • Factors Affecting Tumor Perfusion

        • Disorganized vascular networks
        • Substantial deviations in tumor vessel size
        • Increased interstitial pressure
          • Increased interstitial pressure within tumors considered one of most important factors affecting blood flow within tumors
          • Several factors result in increased interstitial pressure within tumors
            • Increased permeability of tumor vessels
            • Deficiencies on lymphatic drainages, often blocked by proliferating tumors and metastatic deposits
            • Rapid proliferation of tumor cells in relatively confined spaces

      IMAGING

      • Liver Masses

        • Renal Masses

          • Breast Masses

            • Thyroid Masses

              • Ovarian Masses

                Selected References

                1. Dietrich CF et al: How to perform contrast-enhanced ultrasound (CEUS). Ultrasound Int Open. 4(1):E2-E15, 2018
                2. Barr RG et al: Evaluation of indeterminate renal masses with contrast-enhanced US: a diagnostic performance study. Radiology. 271(1):133-42, 2014
                3. Claudon M et al: Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver--update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS. Ultraschall Med. 34(1):11-29, 2013
                4. Fleischer AC et al: Advances in sonographic detection of ovarian cancer: depiction of tumor neovascularity with microbubbles. AJR Am J Roentgenol. 194(2):343-8, 2010
                Related Anatomy
                Loading...
                Related Differential Diagnoses
                Loading...
                References
                Tables

                Tables

                KEY FACTS

                • Terminology

                  • Imaging

                    TERMINOLOGY

                    • Tumor Angiogenesis

                      • Tumor development requires adequate system of blood vessels supplying adequate nutrition and removal of waste products
                      • At earliest stages of neoangiogenesis, tumors recruit vessels from host, most of which come from venous capillary network in form of vascular sinusoids
                      • At same time, tumors produce variety of endothelial growth factors, which initiate new tumor development within tumor and surrounding areas
                      • At early stages, tumors have hypervascular periphery with hyperemic rim of tissue
                      • As tumors progress, central areas may become ischemic due to inability to develop adequate vascular networks
                      • Later, ischemic central areas may undergo necrosis
                    • Tumor Vessel Morphology

                      • Tumor vascular networks usually demonstrate abnormal branching patterns without typical hierarchical order of blood vessel branching seen in normal tissues
                      • Tumor neovascularity can also be differentiated from normal tissues by irregular sizes of vessels and presence of arteriovenous shunts
                      • On more microscopic level, tumor blood vessels are characterized by paucity of smooth muscle within vessel walls, making them more pliable and less pressure resistant
                      • Morphologic appearance of tumor vessels may not allow direct assessment of function of tumor microcirculation or differentiation of benign from malignant tumors due to 20-80% of vascular network being perfused within any given tumor at particular time, while large portions of tumor vascular bed remain dormant
                      • This leads to significant variations in tumor blood flow velocities and tumor vascularity between different areas within same tumor
                    • Factors Affecting Tumor Perfusion

                      • Disorganized vascular networks
                      • Substantial deviations in tumor vessel size
                      • Increased interstitial pressure
                        • Increased interstitial pressure within tumors considered one of most important factors affecting blood flow within tumors
                        • Several factors result in increased interstitial pressure within tumors
                          • Increased permeability of tumor vessels
                          • Deficiencies on lymphatic drainages, often blocked by proliferating tumors and metastatic deposits
                          • Rapid proliferation of tumor cells in relatively confined spaces

                    IMAGING

                    • Liver Masses

                      • Renal Masses

                        • Breast Masses

                          • Thyroid Masses

                            • Ovarian Masses

                              Selected References

                              1. Dietrich CF et al: How to perform contrast-enhanced ultrasound (CEUS). Ultrasound Int Open. 4(1):E2-E15, 2018
                              2. Barr RG et al: Evaluation of indeterminate renal masses with contrast-enhanced US: a diagnostic performance study. Radiology. 271(1):133-42, 2014
                              3. Claudon M et al: Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver--update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS. Ultraschall Med. 34(1):11-29, 2013
                              4. Fleischer AC et al: Advances in sonographic detection of ovarian cancer: depiction of tumor neovascularity with microbubbles. AJR Am J Roentgenol. 194(2):343-8, 2010