Diffuse Large B-Cell Lymphoma in the Portal Vein

Area of Science:

• Oncology
• Hematology
• Vascular Medicine

Background:

• Portal vein tumor thrombus is rare, typically associated with hepatocellular carcinoma.
• Lymphoma rarely presents as a portal vein tumor thrombus, with only four prior cases reported, all due to direct extension.
• Diffuse large B-cell lymphoma (DLBCL) is not typically considered in the differential diagnosis of portal vein thrombi.

Observation:

• A case of an immunocompetent patient with DLBCL presenting solely within the portal vein lumen is described.
• This presentation is unique as it does not involve direct extension from a nodal or extra-nodal mass.
• The liver parenchyma showed no abnormalities, distinguishing it from common causes of portal vein thrombus.

Findings:

• The first documented instance of DLBCL manifesting exclusively as an intravascular tumor thrombus within the portal vein.
• This case expands the known spectrum of DLBCL presentation.
• Demonstrates that DLBCL can occur within the portal vein lumen without contiguous spread.

Implications:

• This case suggests a need to consider DLBCL in the differential diagnosis of unexplained portal vein thrombi, even without apparent primary masses.
• Further research may elucidate the pathogenesis of such intraluminal DLBCL.
• Highlights the importance of thorough investigation for rare oncological presentations.