Lymphoma is a type of cancer that begins in the infection-fighting cells of the immune system, known as lymphocytes. These abnormal white blood cells grow and divide uncontrollably within the lymphatic system, a network of tissues and organs that helps protect the body from illness.
Initial Medical Evaluation
Diagnosis often begins with a healthcare visit for persistent or concerning symptoms. A common initial sign of lymphoma is the painless swelling of one or more lymph nodes, which can appear in areas such as the neck, armpits, or groin. During this initial consultation, the doctor conducts a thorough physical examination, carefully feeling for enlarged lymph nodes, and assessing the liver and spleen for any swelling.
Blood tests are often performed. A complete blood count (CBC) is a common test that measures the levels of different cells in the blood, including red blood cells, white blood cells, and platelets. While a CBC cannot definitively diagnose lymphoma, it can reveal abnormalities such as a high white blood cell count or anemia, which might suggest an underlying issue. A normal CBC does not exclude the possibility of lymphoma, particularly in early stages, as the cancer originates in the lymphatic system and may not immediately affect blood counts unless it has spread to the bone marrow or caused systemic inflammation. Other blood tests may include checking lactate dehydrogenase (LDH) levels, which can be elevated in lymphoma, and assessing kidney and liver function to see if these organs are affected.
Biopsy Procedures for Diagnosis
A biopsy is the only definitive method for diagnosing lymphoma, as it allows for the microscopic examination of tissue to identify cancerous cells. This procedure involves removing a tissue sample, typically from a suspicious lymph node, for analysis by a pathologist. A pathologist confirms lymphoma, its specific type, and growth rate.
Excisional Lymph Node Biopsy
The excisional lymph node biopsy is often considered the preferred method for initial diagnosis because it involves the removal of an entire lymph node. This provides a larger and more intact tissue sample, which is beneficial for a comprehensive evaluation and for conducting additional specialized tests to classify the lymphoma accurately. If the affected lymph node is close to the skin’s surface, the procedure can be performed under local anesthesia, whereas deeper nodes may require general anesthesia. This minor surgical procedure allows pathologists to thoroughly analyze the cellular architecture, which is crucial for distinguishing lymphoma from other conditions and for subtyping the disease.
Core Needle Biopsy
Another method is the core needle biopsy, which involves using a hollow needle to extract a small piece of tissue from a lymph node or suspected area. This procedure is less invasive than an excisional biopsy and can be guided by imaging techniques like ultrasound or CT scans, especially for deeper-seated lesions. While effective, core needle biopsies may yield smaller samples, sometimes requiring further testing or a subsequent excisional biopsy for a conclusive diagnosis.
Bone Marrow Biopsy and Aspiration
Bone marrow biopsy and aspiration are also important diagnostic tools, particularly to determine if lymphoma has spread to the bone marrow. This combined procedure is usually performed on the back of the hip bone. First, a thin needle is used to aspirate a liquid sample of bone marrow; immediately following, a slightly larger needle is inserted to obtain a solid piece of bone marrow tissue. These samples are examined for lymphoma cells and bone marrow health, aiding in disease staging and treatment decisions. In situations where a suspected tumor is located in other areas, such as the skin or liver, specific biopsies like a skin biopsy or liver biopsy may be performed to obtain tissue for examination.
Imaging and Further Diagnostic Tests
After a biopsy confirms a lymphoma diagnosis, imaging studies and additional tests become important for assessing the extent of the disease and guiding treatment. These tools are used to locate tumors, evaluate disease spread, and monitor treatment response, rather than for initial diagnosis.
Computed Tomography (CT) Scans
Computed tomography (CT) scans are routinely used to identify enlarged lymph nodes or tumors within the chest, abdomen, and pelvis. This imaging technique provides detailed cross-sectional images of the body, helping to pinpoint the size and location of affected areas. CT scans are foundational for initial staging, which involves determining how far the lymphoma has spread throughout the body.
Positron Emission Tomography (PET) Scans
Positron emission tomography (PET) scans, often combined with CT scans (PET-CT), are highly valuable for detecting metabolically active cancer cells throughout the entire body. A radioactive tracer (e.g., fluorodeoxyglucose or FDG) is injected, which cancer cells absorb more readily than healthy cells. PET-CT scans can highlight areas of lymphoma activity, including those missed by CT alone, and are particularly useful for staging and evaluating treatment effectiveness by showing how well the cancer is responding.
Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging (MRI) provides detailed images of soft tissues and is frequently used to assess potential lymphoma involvement in the brain and spinal cord. Unlike CT scans, MRI does not use ionizing radiation and offers different types of tissue contrast, making it suitable for specific areas where detailed soft tissue visualization is paramount.
Lumbar Puncture
When central nervous system involvement is suspected, a lumbar puncture may be performed. This procedure involves collecting a sample of cerebrospinal fluid (CSF) from the spinal canal to check for the presence of lymphoma cells. These tests collectively provide a comprehensive picture of the disease, enabling healthcare teams to formulate personalized treatment strategies.