How Is T-Cell Lymphoma Diagnosed?

Diagnosing T-cell lymphoma involves a comprehensive evaluation that includes a physical examination, patient history, and a variety of tests. The results not only confirm the diagnosis but also help to determine the stage of the disease, which is crucial for planning the appropriate treatment.

What are the Blood Tests that Detect T-Cell Lymphoma? 

Complete blood count (CBC): A CBC measures the number of different types of blood cells, including red blood cells, white blood cells, and platelets. Abnormalities in the CBC can provide important diagnostic clues. In T-cell lymphoma, the following CBC findings may be observed:

• Anemia: T-cell lymphoma can lead to anemia, characterized by a low red blood cell count and decreased hemoglobin levels, resulting in symptoms such as fatigue and weakness.
• Leukocytosis: Elevated white blood cell counts, particularly an increased number of lymphocytes and monocytes, may be present in T-cell lymphoma.
• Thrombocytopenia: Low platelet counts can occur in T-cell lymphoma, leading to a higher risk of bleeding and easy bruising.

Blood chemistry tests, measure the levels of various substances in the blood, including liver and kidney function, which can be affected by lymphoma.

• Lactate dehydrogenase (LDH): LDH is an enzyme that is often elevated in the blood when there is cell damage or increased cell turnover, as seen in T-cell lymphoma. Elevated LDH levels may be associated with a more aggressive disease.
• Beta-2 microglobulin (B2M): Beta-2 microglobulin is a protein found on the surface of some immune cells. Elevated levels of this protein can indicate more advanced or aggressive lymphomas, including T-cell lymphoma
• Creatinine is a marker of kidney function; it helps determine if the kidneys are working properly. 
• Liver function tests: they are a series of tests obtained from the blood, that analyze enzymes and proteins produced by the liver.

Immunophenotyping: This test identifies cells based on the proteins or markers present on their surface. It can help determine whether a lymphoma is of the T-cell or B-cell type.

• A T-cell is a type of white blood cell called a lymphocyte.
• A B-cell is a type of white blood cell that makes infection-fighting proteins called antibodies.

Why Am I Being Tested for Virus?

Some T-cell lymphoma types are derived from specific viruses that create an abnormal immune response. These viruses are: 

• Epstein-Barr Virus: a test called PCR is performed to detect this virus which is linked to several types of lymphoma, especially to extranodal nasal-type NK/T cell lymphoma.  Although it is a common virus transmitted by saliva, not all patients who get it are at risk of developing lymphoma.  
• Human T-lymphotropic virus 1 (HTLV-1): is also detected by PCR, and this virus is linked to the development of T-cell lymphoma and leukemia in approximately 5% of patients. It is transmitted through bodily fluids including blood, breast milk and semen. According to the World Health Organization, an estimated 5–10 million people globally are infected with HTLV-1, although that number is probably higher due to a lack of reliable data. 

What Autoimmune Disease Test Are Performed? 

The most common autoimmune disease linked to T-cell lymphoma is celiac disease, it can be detected by a blood sample or a biopsy of the small intestine. Not all celiac disease patients develop lymphoma, but it can be considered a risk factor to develop enteropathy-associated T-cell lymphoma (EATL), an aggressive type of lymphoma with a poor prognosis, that develops in the intestines. 

Why are Lymph Nodes Analyzed? 

Lymph nodes are one of the first signs of T-cell lymphoma, therefore it's important to analyze abnormal enlargement of lymph nodes. 

• Lymph node biopsy: The diagnosis of T-cell lymphoma is confirmed by removing part or all of an enlarged lymph node with a biopsy. This procedure may be performed with local anesthesia if the involved tissue is relatively close to the skin's surface. If the node is deeper, general anesthesia is required. The cells from the tissue are then examined in detail using a microscope and other techniques.
• Immunohistochemistry: This test involves a staining process of the biopsy sample that adds a chemical marker to immune cells. The cells are then studied under a microscope.
• Molecular testing: The biopsy sample will undergo tests to look for specific DNA mutations and protein levels. 

Does T-Cell Lymphoma Diagnosis Require Bone Marrow Tests?

Yes, the bone marrow is affected in 20-40% of T-cell lymphoma cases, and it is considered the gold standard test to detect BMI.

• Bone marrow aspiration and biopsy: These tests involve taking a small amount of bone marrow, usually from the hip bone, and examining it under a microscope to look for lymphoma cells. A bone marrow biopsy is not necessary if a PET/CT scan shows that the bone is affected.
• Flow cytometry: Flow cytometry analyzes the cell surface markers and characteristics of bone marrow cells. It can help identify and quantify lymphoma cells and assess their immunophenotype.
• Cytogenetic analysis: Cytogenetic analysis involves the examination of the chromosomes within the bone marrow cells. It can detect chromosomal abnormalities or genetic mutations that may be associated with T-cell lymphoma.
• Molecular testing: Molecular testing may be performed to identify specific genetic mutations or rearrangements present in T-cell lymphoma. This testing can provide additional diagnostic and prognostic information.
• Fluorescence in situ hybridization (FISH): This test finds changes in chromosomes called translocations. Since this test doesn't need growing cells, it can be done on a bone marrow sample or blood sample. 

Why Do I Need a Skin Biopsy? 

Some people can start with skin symptoms only and later discover that they have T-cell lymphoma in the skin, so a skin tissue sample is required to confirm the diagnosis. Usually, skin biopsies are performed with local anesthesia and heal in two weeks or less. 

What are the Imaging Tests for T-Cell Lymphoma?

• Computed Tomography (CT) scan: This test uses X-rays to make detailed pictures of sections of the body, such as the chest, abdomen, and pelvis, where lymphoma often occurs.
• Positron Emission Tomography (PET) scan: This test uses a small amount of radioactive glucose (sugar) to find cancer cells in the body. The areas where the glucose is taken up appear 'hot' on the scan and can indicate the presence of lymphoma.
• Magnetic Resonance Imaging (MRI): This test uses magnetic fields, not X-rays, to produce detailed images of the body. It can measure the size of the lymphoma.

It's important to note that the diagnosis and classification of T-cell lymphoma are complex and require a comprehensive evaluation by a team of specialists. A complete diagnosis requires a physical examination,  analysis of a bone marrow sample, and genetic testing. 

Continue learning about T-cell lymphoma with our comprehensive 101 pages!

LEARN ALL ABOUT T-CELL LYMPHOMA

Sources: 

• https://www.ncbi.nlm.nih.gov/books/NBK564354/ 
• https://ashpublications.org/blood/article/134/Supplement_1/4039/424320/Utility-of-Bone-Marrow-Biopsy-in-the-Staging-of-T 
• https://www.who.int/news-room/fact-sheets/detail/human-t-lymphotropic-virus-type-1 
• https://www.cdc.gov/epstein-barr/about/index.html#cdc_disease_basics_population-who-is-at-risk