Hodgkin’s Lymphoma (HL) is a cancer originating in the lymphatic system, part of the immune system. It is characterized by the uncontrolled growth of a specific type of abnormal white blood cell. While blood tests cannot definitively diagnose Hodgkin’s Lymphoma, they are an important first step in screening patients and guiding further investigation. Standard blood work provides a non-specific yet informative look at the body’s function and its reaction to a potential disease process like HL. Analyzing various markers in the blood helps physicians gather clues that point toward the need for a definitive, tissue-based diagnosis.
Initial Blood Screening and Routine Indicators
The complete blood count (CBC) is a routine blood test that measures the cellular components circulating in the blood, including red blood cells, white blood cells, and platelets. An abnormal CBC result can indicate the potential presence of Hodgkin’s Lymphoma, though it is not a direct measure of the cancer itself. The test evaluates the quantities of these cell types, which are produced in the bone marrow and can be affected by the lymphoma.
HL can lead to anemia, characterized by low red blood cell or hemoglobin levels. This anemia often results from chronic inflammation associated with the cancer. Changes in white blood cell counts are also possible, sometimes showing an elevated number of white blood cells, which can also signal infection.
Lymphocyte counts, a type of white blood cell, may be lower than normal in some HL cases, a finding known as lymphopenia. Platelet counts, which measure clotting cells, may also be affected, appearing higher or lower than the typical range. These changes are non-specific and can be caused by numerous other conditions.
Interpreting Systemic Biomarkers
Beyond the CBC, other blood tests measure systemic biomarkers that reflect inflammation and disease activity throughout the body. These tests are valuable for raising suspicion of a serious underlying condition, though they remain non-diagnostic for Hodgkin’s Lymphoma. The Erythrocyte Sedimentation Rate (ESR) measures how quickly red blood cells settle in a test tube. A high ESR indicates increased inflammation and is often elevated in people with active HL.
C-Reactive Protein (CRP) is a protein produced by the liver in response to inflammation and tissue damage. An elevated CRP level is a common finding in HL patients, reflecting the systemic inflammatory response triggered by the cancer. Both ESR and CRP are useful for initial evaluation and for monitoring treatment effectiveness after a diagnosis is confirmed.
Lactate Dehydrogenase (LDH) is an enzyme released into the bloodstream when cells are damaged or rapidly dividing. High LDH levels signal high cellular turnover, which is characteristic of aggressive or bulky disease. While these systemic biomarkers are not conclusive, their elevation strongly suggests a need for further investigation and can help assess the prognosis of the disease.
Confirmatory Diagnosis and Subsequent Testing
Since blood tests only provide indications, the confirmation of Hodgkin’s Lymphoma requires a tissue biopsy. This procedure involves surgically removing an entire lymph node (excisional biopsy) or a small piece of tissue (core needle biopsy) for laboratory analysis. The choice of biopsy depends on the location and size of the suspicious area.
The pathologist examines the tissue under a microscope looking for Reed-Sternberg cells. These large, abnormal cells are the hallmark of classic Hodgkin’s Lymphoma. Their identification in the tissue sample is necessary to confirm the diagnosis.
Once the diagnosis is confirmed, imaging tests such as Positron Emission Tomography (PET) or Computed Tomography (CT) scans are crucial for staging the disease. These scans determine where the lymphoma has spread, which dictates the appropriate treatment plan. Blood tests are also performed to establish baseline organ function, such as kidney and liver health, before treatment begins.