A finding of hypervascularity in a medical imaging report can be alarming, but it does not automatically mean a person has cancer. Hypervascularity describes a region of tissue with an unusually high concentration of blood vessels or significantly increased blood flow. While frequently associated with malignant tumors, many common, non-cancerous conditions also cause this increase in blood flow.
Understanding Hypervascularity
Hypervascularity occurs when a specific area of the body receives more blood than the surrounding tissue. This happens either because existing blood vessels widen (hyperemia) or because new blood vessels form (neovascularization). This increased blood flow supplies necessary oxygen and nutrients to rapidly growing or highly active tissue.
Medical imaging techniques, such as contrast-enhanced Computed Tomography (CT) or Magnetic Resonance Imaging (MRI), detect this increased vascularity. When a contrast dye is injected, a hypervascular lesion will enhance brightly and quickly on the scan. The interpretation of this enhancement pattern helps doctors differentiate between various causes.
The Connection to Malignancy
Hypervascularity is often linked to cancer due to a process called angiogenesis. Malignant tumors undergo uncontrolled, rapid cell division, which demands a constant supply of nutrients and oxygen. To meet this high metabolic demand, tumor cells release chemical signals, most notably Vascular Endothelial Growth Factor (VEGF).
VEGF compels nearby host blood vessels to sprout new branches and penetrate the tumor mass. This newly formed tumor vasculature is typically chaotic, leaky, and disorganized, which is a hallmark of malignancy. The resulting irregular blood network makes the tumor appear intensely bright on contrast-enhanced medical scans. Physicians look for this specific pattern of intense, early enhancement to flag a lesion as potentially cancerous.
Other Causes of Increased Blood Flow
Hypervascularity is not exclusive to malignant tumors; any condition triggering a biological response involving growth or repair can increase blood flow. Inflammation, whether acute due to infection or chronic due to an autoimmune condition, causes surrounding blood vessels to expand, resulting in hyperemia. An abscess or chronic inflammation, such as in an arthritic joint, will often appear hypervascular on imaging.
Benign masses are also a frequent cause of this finding. Non-cancerous growths like a hepatic hemangioma, the most common benign liver tumor, are tangles of blood vessels that show marked enhancement on scans. Other benign liver lesions, such as Focal Nodular Hyperplasia (FNH), can also be intensely hypervascular due to abnormal blood vessel structure. Vascular anomalies, like arteriovenous shunts, also create localized areas of high blood flow unrelated to cancer.
Next Steps After a Hypervascular Finding
When a hypervascular lesion is identified, the next steps focus on differentiating its cause by analyzing specific imaging characteristics. A radiologist examines the lesion’s enhancement pattern, looking for features like size, border irregularity, and the presence of “washout.” Malignant lesions, such as hepatocellular carcinoma, often show rapid, intense enhancement followed by a quick washout of the contrast material as it leaks out of the disorganized tumor vessels.
In contrast, benign tumors like hemangiomas typically show a slow, persistent filling-in of the contrast material over time. If imaging characteristics are inconclusive or highly suspicious, the definitive diagnostic tool is a biopsy, such as a Fine Needle Aspiration or a core needle biopsy. This procedure removes a small tissue sample for a pathologist to examine under a microscope, which is the only way to confirm or rule out the presence of cancer cells. The final diagnosis is made by combining the clinical history, laboratory results, detailed imaging features, and the conclusive findings from the tissue pathology.