Lymphoma is a cancer that begins in lymphocytes, a type of white blood cell central to the body’s immune system. The disease originates within the lymphatic system, a network of vessels, tissues, and organs, including the lymph nodes, spleen, and bone marrow. Discovering a lymphoma diagnosis is rarely a single moment, but rather a progression of observations and medical tests that link vague symptoms to a confirmed identification of the disease.
Recognizing the Early Signals
The most common sign of lymphoma is a painless, enlarged lymph node, felt as a firm lump in the neck, armpit, or groin. This swelling is caused by a buildup of cancerous lymphocytes. While lymph nodes often swell due to common infections, a persistent swelling that does not resolve within a few weeks warrants medical attention.
Lymphoma can also cause systemic symptoms, collectively known as “B symptoms.” These include drenching night sweats that soak clothes and bedding. Other characteristic B symptoms are a persistent, unexplained fever that comes and goes, and unintentional weight loss. This weight loss is defined as ten percent or more of one’s body weight within six months, without dieting or increased physical activity.
Initial Medical Evaluation and Imaging
When a patient presents with these symptoms, the physician begins a medical evaluation to narrow the possibilities. The initial physical examination focuses on palpating the lymph nodes to assess their size and texture, and checking for enlargement of the spleen or liver. This is followed by preliminary, non-invasive tests intended to check for signs of disease activity.
Routine blood work includes a Complete Blood Count (CBC) to check for abnormal levels of red and white blood cells, which can suggest bone marrow involvement. A blood chemistry panel measures lactate dehydrogenase (LDH), an enzyme often elevated in the presence of rapidly dividing cancer cells. Following blood tests, imaging studies visualize the extent of abnormal growths. A computed tomography (CT) scan is typically ordered for the chest, abdomen, and pelvis to map out enlarged lymph nodes and affected organs.
The Confirmatory Step: Biopsy
While initial tests may suggest lymphoma, the definitive diagnosis requires obtaining a tissue sample for analysis. A biopsy is the most important procedure because it allows a pathologist to examine the cells under a microscope. For lymph nodes, an excisional biopsy, which removes the entire node, is often preferred. This preserves the tissue structure necessary for pathologists to accurately classify the specific subtype of lymphoma.
If full node removal is not feasible due to its location, a core needle biopsy may be used to extract a small cylinder of tissue. A fine-needle aspiration, which only collects individual cells, is usually inadequate for an initial diagnosis. A bone marrow aspiration and biopsy is also frequently performed, typically from the hip bone, to determine if the cancer has spread to the bone marrow. The pathologist uses specialized stains and genetic tests on the sample to confirm malignant lymphocytes and determine their characteristics.
Understanding the Diagnosis
Once the biopsy confirms the presence of lymphoma, the process shifts to classifying it precisely. The pathologist’s detailed analysis identifies the specific subtype, broadly categorizing it as either Hodgkin lymphoma or non-Hodgkin lymphoma. This distinction is based on cellular features, such as the presence of Reed-Sternberg cells, which characterize Hodgkin lymphoma.
The final step in understanding the diagnosis is staging, which describes how far the cancer has spread in the body. Physicians use the Ann Arbor staging system or the Lugano classification, which assigns a stage from I to IV based on the number and location of affected lymph node regions. The stage is further modified with letters, such as ‘B’ if the patient has experienced systemic symptoms, or ‘E’ if the disease has spread outside the lymphatic system into an organ. Knowing the exact subtype and stage provides the comprehensive picture necessary for treatment planning.