DLBCL: Pathology and Molecular Results

This page is for people reading a DLBCL pathology report. It explains the main biopsy findings, gene test results, the IPI risk score, and how these results connect to treatment.

DLBCL is diagnosed from a lymph-node or tissue biopsy. An excisional biopsy, which removes the whole node, confirms the diagnosis correctly about 98% of the time. A core needle biopsy, a thinner sample, still works well and confirms the diagnosis about 92% of the time. Either way, a hematopathologist, a specialist in blood and lymph tissue, should review the slides. This matters because DLBCL can look similar to other lymphomas under a basic exam.

Your report will likely mention CD20, a protein on the surface of the lymphoma cells. Nearly all DLBCL cases are CD20-positive, which is what allows treatment with CD20-targeted antibody drugs. The pathologist may also test whether the cancer looks and behaves more like a germinal-center cell or an activated B-cell. This is called cell-of-origin testing, and it can affect prognosis (the likely outlook).

Some DLBCL cells have extra copies or rearrangements of the MYC and BCL2 genes, sometimes both together. This combination is linked to disease that is harder to treat. It may push your team toward a more intensive chemotherapy regimen instead of the usual first choice. Ask whether your tissue was tested for these changes.

Doctors often calculate a risk score called the IPI. It adds up five factors:

• Age
• Stage
• Performance status, a measure of how well you manage daily activities
• LDH, a blood test
• How many areas outside the lymph nodes are involved

Higher scores are linked to lower five-year survival in large studies. Rates range from about 96% in the lowest-risk group to about 33% in the highest-risk group. The IPI is a planning tool, not a prediction for one individual.

The standard first treatment for DLBCL is a combination called R-CHOP: rituximab plus four chemotherapy drugs. Some people, particularly those with certain high-risk features, may instead get Pola-R-CHP, which swaps in a drug called polatuzumab vedotin. A related but distinct fast-growing lymphoma is called primary mediastinal B-cell lymphoma. It often responds well to a regimen called dose-adjusted R-EPOCH.

If DLBCL comes back, or does not respond to first treatment, options include different chemotherapy combinations. Another option is CD19-directed CAR T-cell therapy, which uses your own reprogrammed immune cells. NCI reports that in trials involving people with large cell lymphoma, more than 30% of participants were alive with no evidence of cancer five years after this treatment.

Cell-of-origin testing, MYC and BCL2 studies, and other marker panels can take one to two weeks. Ask whether your treatment start date can wait for these results, since they can change which regimen your team recommends.

• Was my tissue reviewed by a hematopathologist experienced in lymphoma?
• What is my cell-of-origin result, and were MYC and BCL2 tested?
• What is my IPI score, and how does it shape the plan?
• Is R-CHOP the recommended first treatment, or does something else fit better?
• If this comes back, what would the next options be?

• National Cancer Institute — Aggressive B-Cell Non-Hodgkin Lymphoma Treatment (PDQ).
• National Cancer Institute — CAR T Cells: Engineering Immune Cells to Treat Cancer.