Lymphovascular Invasion (LVI): Definition
Lymphovascular invasion (LVI) means cancer cells have entered a lymphatic or blood vessel. Lymphatic vessels are thin channels that carry lymph, a fluid. Blood vessels carry blood. Cancer cells inside either type of vessel can travel away from the tumor. LVI is a finding that a pathologist reports after examining a tumor under the microscope.
LVI is a finding, not a diagnosis. It describes what the pathologist saw in the tissue. This article explains what lymphovascular invasion means, how pathologists identify it, what the wording on your report means, and why the finding matters.
What does lymphovascular invasion mean?
A growing tumor can invade the surrounding tissue. Lymphovascular invasion happens when tumor cells invade a lymphatic or blood vessel. Once inside, the cells can travel through the lymph or the blood to other parts of the body.
Lymphatic vessels drain into the lymph nodes, so tumor cells in lymphatic vessels can spread to nearby nodes. Tumor cells in blood vessels can spread to distant organs. Doctors call this kind of spread metastasis. Pathologists use the word lymphovascular because it covers both routes.
How is lymphovascular invasion different from vascular and lymphatic invasion?
Reports use three related terms for tumor cells inside vessels:
- Lymphovascular invasion. Tumor cells are inside a lymphatic or blood vessel. Pathologists use this term when the vessel could be either type or when both types are involved. Gynecologic reports may say lymphovascular space invasion (LVSI).
- Lymphatic invasion. Tumor cells are inside a lymphatic vessel. See lymphatic invasion.
- Vascular invasion. Tumor cells are inside a blood vessel, usually a vein. See vascular invasion, also called angioinvasion.
The distinction is often hard to make on routine slides. Small lymphatic vessels and tiny blood vessels look alike. For this reason, many reports use the combined term.
How is lymphovascular invasion identified?
The pathologist examines thin slices of the tumor and surrounding tissue. The pathologist looks for clusters of tumor cells within a space lined by vessel cells. The finding can be hard to confirm. Tissue can shrink during processing, leaving a gap around a group of tumor cells. This gap, called retraction, can look like a vessel.
To avoid a mistake, the pathologist may use extra tests:
- Immunohistochemistry. immunohistochemistry uses antibodies to mark the cells that line vessels. D2-40 marks lymphatic vessels. CD31, CD34, and ERG mark blood vessels.
- Special stains. An elastic special stain outlines the elastic layer in the wall of a vein. This helps confirm that a space is a vein.
What might my report say about lymphovascular invasion?
Reports state the result in a few standard ways. Each laboratory phrases it a little differently:
- Present, identified, or positive. The pathologist saw tumor cells inside a lymphatic or blood vessel.
- Not identified, absent, or negative. The pathologist did not see tumor cells inside a vessel. The pathologist checks only the slides prepared from the tumor, so this result lowers the concern but cannot rule out invasion.
- Indeterminate or suspicious. Something looked like lymphovascular invasion, but the pathologist could not be sure. Retraction is a common cause.
- TNM codes. Some reports use staging codes. L0 or L1 describes lymphatic invasion, and V0, V1, or V2 describes venous invasion. A zero means no invasion was found.
Does lymphovascular invasion mean the cancer has spread?
Lymphovascular invasion does not mean the cancer has spread. It means the cancer has a route to spread, and the chance of spread is higher. Many people with LVI never develop spread, and some people without it do. Imaging tests and the results from lymph nodes show whether cancer has reached other places.
Why is lymphovascular invasion important?
Pathologists report LVI for many cancers. Doctors consider it an adverse feature. The finding matters in three ways:
- Risk of spread. In a polyp that contains cancer, lymphatic invasion raises the risk of spread to lymph nodes. The care team weighs this finding after removing the polyp.
- Risk of recurrence. In testicular germ cell tumors, LVI is a recognized high-risk factor for the cancer coming back.
- Prognosis. In many cancers, LVI points to a worse prognosis. It is one of several findings doctors consider together, and it never predicts the outcome on its own.
Pathologists usually record LVI as a separate finding next to the stage. The TNM staging system has its own categories for it. In some cancers, such as hepatocellular carcinoma, vascular invasion changes the tumor stage.
How does lymphovascular invasion affect treatment?
LVI does not decide treatment on its own. The care team weighs it with the tumor type, grade, stage, and other findings in your report. In some cancers, LVI may lead the team to consider additional treatment after surgery, extra lymph node testing, or closer follow-up. Your doctor can explain how the finding applies to your situation.
Questions to ask your doctor
- Did the pathologist find lymphovascular invasion in my tumor?
- Does my report say whether the vessel was a lymphatic vessel or a blood vessel?
- If the result is indeterminate, what made it uncertain?
- Were special stains or immunohistochemistry used to confirm the finding?
- Were the lymph nodes checked for cancer?
- Does lymphovascular invasion change my cancer stage?
- Does this finding affect my treatment options or follow-up?
- What tests will show whether the cancer has spread?