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PubMed This is a summary of 19 peer-reviewed journal articles Updated
Oncology

Cracking the Code: Understanding Your Pathology Report

At a Glance

A Non-Hodgkin lymphoma pathology report uses an excisional biopsy to identify your specific cancer subtype. Key details include CD20 status for targeted treatments, the Ki-67 index for growth rate, and genetic testing to check for double-hit lymphoma.

Your pathology report is the “blueprint” for your treatment. It is a detailed document written by a pathologist—a doctor who specializes in studying tissues and cells—to identify exactly which type of Non-Hodgkin Lymphoma (NHL) you have [1]. Because there are so many subtypes of NHL, getting this report right is the most critical step in your care.

The Gold Standard: Excisional Biopsy

You may have had a Fine Needle Aspiration (FNA), where a thin needle is used to pull out a few cells. While FNA is a helpful first step to see if cancer is present, it is usually not enough for a final NHL diagnosis [2][3].

For a definitive diagnosis, doctors prefer an excisional biopsy—the surgical removal of an entire lymph node [1]. This is the “gold standard” because it allows the pathologist to see the architecture of the node. They need to see not just what the individual cells look like, but how they are arranged and how they interact with the tissue around them [4].

Decoding the Lab Tests

Pathologists use two main technologies to “fingerprint” your lymphoma:

  • Immunohistochemistry (IHC): The pathologist applies specialized “stains” to a slice of your tissue. These stains stick to specific proteins on the surface of the cancer cells, making them change color under a microscope [5][6].
  • Flow Cytometry: This test takes a sample of living cells and passes them through a laser. It identifies the “markers” on the surface of thousands of cells in seconds, helping to confirm if the cells are B-cells, T-cells, or NK-cells [5][7].

Key Markers to Look For

Your report will list many markers, often starting with “CD” (Cluster of Differentiation) followed by a number.

  • CD20: This is a protein found on the surface of almost all B-cell lymphomas. If you are CD20 positive, you may be eligible for targeted treatments like rituximab, which specifically seeks out and attaches to this protein [8][9].
  • CD10 and BCL2: These markers help identify where the lymphoma started (its “cell of origin”) and can signal more aggressive behavior [10][11].
  • Ki-67: This is a “proliferation index.” It is given as a percentage (e.g., 80%) and tells you what portion of the cancer cells are actively dividing at that moment. A higher number generally means a more aggressive, faster-growing lymphoma [12].

“Double-Hit” and EBV Status

Some reports include specialized genetic testing called FISH (Fluorescence In Situ Hybridization).

  • Double-Hit Lymphoma: This occurs when the cancer cells have “rearrangements” (genetic swaps) in two specific genes: MYC and BCL2 (or sometimes BCL6). If three genes are involved, it is called triple-hit [13][14]. These are considered high-grade, aggressive lymphomas that often require more intensive treatment than standard cases [15][16].
  • EBV Status: The Epstein-Barr Virus is a common virus that can sometimes drive the growth of lymphoma. Knowing if your lymphoma is EBV-positive helps doctors understand why it may have developed and can occasionally influence treatment choices [17][18].

Your Pathology Report Checklist

A complete NHL pathology report should ideally include the following:

  1. Procedure Type: (e.g., Excisional biopsy, core biopsy) [1]
  2. Specific Subtype: (e.g., Diffuse Large B-cell Lymphoma) [19]
  3. Lineage: (B-cell, T-cell, or NK-cell) [7]
  4. Cell of Origin: (e.g., Germinal Center B-cell (GCB) vs. Activated B-cell (ABC)) [10]
  5. IHC Markers: (Results for CD20, CD10, BCL2, BCL6, MYC) [5]
  6. Proliferation Index: (Ki-67 percentage) [12]
  7. Genetic Testing: (FISH results for MYC, BCL2, and BCL6 translocations) [13]

Common questions in this guide

What is the difference between an excisional biopsy and a fine needle aspiration?
An excisional biopsy removes the entire lymph node, allowing the pathologist to see the tissue structure. A fine needle aspiration only pulls out a few cells, which is often not enough to confirm a definitive Non-Hodgkin lymphoma diagnosis.
What does CD20 positive mean on my lymphoma pathology report?
CD20 is a specific protein found on the surface of most B-cell lymphomas. If your report says you are CD20 positive, it means you may be a candidate for targeted treatments like rituximab that specifically attack cells with this protein.
What is the Ki-67 proliferation index?
The Ki-67 index is a percentage that shows how many of your cancer cells are actively dividing. A higher Ki-67 percentage usually indicates a faster-growing, more aggressive lymphoma.
What is double-hit lymphoma?
Double-hit lymphoma means the cancer cells have genetic mutations in two specific genes, typically MYC and BCL2 or BCL6. These are aggressive lymphomas that often require more intensive treatment plans than standard cases.
Why is the cell of origin important in my biopsy results?
The cell of origin identifies the specific type of immune cell where your lymphoma started, such as a Germinal Center B-cell or an Activated B-cell. This information helps your doctor determine the cancer's behavior and choose the best treatment approach.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Was my biopsy an excisional biopsy or a core/fine-needle biopsy, and was there enough tissue for a definitive subtype diagnosis?
  2. 2.Does my report show 'double-hit' or 'triple-hit' rearrangements in MYC and BCL2/BCL6?
  3. 3.What is my Ki-67 proliferation index, and what does it tell us about how fast my lymphoma is growing?
  4. 4.Is my lymphoma positive for CD20, and does that make me a candidate for targeted therapies like rituximab?
  5. 5.Did the report mention my 'cell of origin' (e.g., Germinal Center B-cell vs. Activated B-cell)?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (19)
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This page explains Non-Hodgkin lymphoma pathology terminology for educational purposes only. Always consult your oncologist or pathologist to properly interpret your specific biopsy results.

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