Concept:

100% certainty observation is tumor invading vein.

Definition:

Observation associated with definite tumor in vein.

Criterion:

• Definite enhancing soft tissue in vein.

If unsure about category

• Do not categorize as LR5V
• Characterize as LR-3, LR-4, or LR-5 using Table

Reporting:

• Must be reported.

Management implications:

• Tumor in vein is considered a contraindication to liver transplantation.
• Tumor in vein may limit eligibility for local ablative therapies, such as transarterial embolization

Comments:

• Applies even if parenchymal component of observation is not identified at imaging.
• The term tumor in vein is preferred over the term tumor thrombus 
• Rationale: the pathological spectrum ranges from thrombus with scant tumor cells to solid tumor with scant thrombus.