Makindo Medical Notes

Related Subjects: |Hodgkin Lymphoma |Non Hodgkin Lymphoma |Diffuse large B-cell lymphoma |Intravascular large B-cell lymphoma |Mantle cell lymphoma |Marginal Zone Lymphoma |Gastric (MALT) Lymphoma |Primary CNS Lymphoma (PCNSL) |Burkitt's lymphoma |Follicular Lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare and aggressive subtype of extranodal non-Hodgkin lymphoma characterized by the selective proliferation of neoplastic B-cells within the lumina of small to medium-sized blood vessels. This unique growth pattern typically results in the absence of a distinct extravascular tumor mass.

About

• Selective intravascular growth of neoplastic lymphocytes.
• No obvious extravascular tumor mass is present; hence, it is considered a rare extranodal lymphoma.

Aetiology

• It is a subtype of extranodal diffuse large B-cell lymphoma (DLBCL).
• Some cases have been found to be EBV positive.
• Organ involvement varies, with the central nervous system affected in approximately 60% of cases, skin in 7%, bone marrow and spleen in 11%, and lungs in 7%.

Clinical Features

• Most commonly seen in elderly patients.
• May present with progressive skin rashes that can mimic other dermatological conditions.
• Splenomegaly is a frequent finding.
• Central nervous system involvement may result in encephalopathy and other neurological deficits.
• Can be associated with haemophagocytic syndrome, particularly in the Asian variant, which presents with fever, thrombocytopenia, and splenomegaly, along with bone marrow involvement.

Investigations

• FBC: Often shows anemia; inflammatory markers such as CRP and LDH are markedly elevated.
• Skin Biopsy: May reveal vascular involvement with large lymphoma cells; immunohistochemistry typically demonstrates CD20 positivity.
• PET Scan: Shows increased uptake in affected regions such as the lungs, bone marrow, and renal cortex.
• Flow Cytometry: Performed on peripheral blood may reveal a clonal B-cell population.
• Lumbar Puncture (LP): CSF analysis may be normal despite CNS involvement.
• CXR: Often unremarkable.

Pathology

• Neoplastic lymphoma cells are found obstructing small blood vessels.
• Tumor cells are immunohistochemically positive for CD20, confirming B-cell lineage.

Management

• IVLBCL is highly aggressive, with a high overall mortality rate and short survival times. Unfortunately, diagnosis is often made post mortem.
• Management involves prompt systemic chemotherapy (often with regimens used for diffuse large B-cell lymphoma), and in some cases, immunotherapy (e.g., Rituximab). Supportive care and management of complications such as coagulopathy or organ failure are also essential.

References

• Intravascular Large B-Cell Lymphoma: Clinical and Histopathologic Findings