Hodgkin’s lymphoma (HL) is a cancer that begins in the lymphatic system, part of the body’s immune defense. The disease involves the uncontrolled growth of a specific white blood cell, the lymphocyte. Testing for HL is a methodical process that progresses from initial suspicion to a definitive diagnosis and assessment of disease extent. This process starts with recognizing signs and moves through preliminary evaluations before reaching confirmatory tissue analysis.
Recognizing Initial Indicators
The initial indicator that often prompts a medical visit is the painless swelling of lymph nodes, which are small, bean-shaped glands found throughout the body. These enlarged nodes are typically noticed in the neck, above the collarbone, in the armpit, or in the groin area. Unlike nodes swollen from a common infection, those related to Hodgkin’s lymphoma are usually firm, rubbery, and do not shrink quickly.
Patients may also experience systemic signs, often referred to as “B symptoms,” which are highly suggestive of a hematologic malignancy. These include drenching night sweats, unexplained fevers, and significant, unintentional weight loss. Losing more than 10% of total body weight over six months is a notable indicator. Persistent itching or profound fatigue may also be present, driving the need for a medical investigation.
Certain risk factors can heighten suspicion when symptoms are present. Hodgkin’s lymphoma is most commonly diagnosed in two age groups: young adults (20s and 30s) and older adults (over 65). A family history of lymphoma or a prior infection with the Epstein-Barr virus (EBV) are factors that may increase risk. When these symptoms and risk factors align, the next step is a comprehensive medical evaluation.
The Initial Medical Evaluation
The first step is a thorough physical examination and a detailed review of the patient’s medical history. The provider checks the neck, armpits, and groin for enlarged lymph nodes, noting their size, texture, and pain level. They also palpate the abdomen to check for an enlarged spleen or liver, as these organs can be affected.
Initial screening blood tests are often ordered to look for general signs of disease or inflammation, though they cannot definitively diagnose Hodgkin’s lymphoma. A Complete Blood Count (CBC) measures white blood cells, red blood cells, and platelets, which can show abnormalities. Basic chemistry panels assess overall organ function and measure markers such as lactate dehydrogenase (LDH), which can be elevated in people with lymphoma.
Imaging tests provide an internal view to check for affected lymph nodes not visible externally. A chest X-ray is commonly used to check for enlarged lymph nodes within the chest cavity, particularly in the mediastinum. If warranted, a computed tomography (CT) scan provides detailed, cross-sectional images of the chest, abdomen, and pelvis. These preliminary tests help narrow the possibilities and justify the need for definitive tissue analysis.
Confirmatory Diagnostic Procedures
The only way to confirm Hodgkin’s lymphoma is through a biopsy, which involves surgically removing tissue for examination. The preferred method is an excisional biopsy, where the entire affected lymph node is removed. This procedure provides the pathologist with the most complete sample, allowing for a comprehensive assessment of the tissue architecture.
A core needle biopsy, which removes a small cylinder of tissue, may be an alternative if an excisional biopsy is difficult due to the node’s location. However, the small sample size can sometimes make diagnosis challenging. The tissue is sent to a pathologist who examines it under a microscope for characteristic signs of the disease.
The definitive finding for classical Hodgkin’s lymphoma is the presence of Reed-Sternberg cells. These are large, abnormal lymphocytes with multiple nuclei that resemble “owl’s eyes.” Immunophenotyping is used to identify specific proteins on the cell surface, confirming the diagnosis and classifying the subtype of HL.
Reed-Sternberg cells typically express the proteins CD30 and CD15. This profile is instrumental in distinguishing HL from other types of lymphoma or non-cancerous conditions. The final pathology report confirms the presence and type of the disease.
Determining Disease Extent (Staging)
Once the diagnosis is confirmed, additional tests are required to determine the extent of the cancer’s spread, a process known as staging. This information is crucial for planning the most effective treatment strategy. The primary tool for comprehensive staging is the combined Positron Emission Tomography (PET) and CT scan (PET-CT).
During a PET scan, a radioactive sugar substance is injected into the bloodstream and absorbed by metabolically active cells, including cancer cells. The PET component highlights areas of active disease throughout the body. The CT component provides detailed anatomical images for precise localization, making the PET-CT highly effective for identifying all sites of involvement.
Detailed CT scans of the neck, chest, abdomen, and pelvis are also part of the staging workup to measure the size of affected lymph nodes or masses. A bone marrow biopsy, historically a standard staging procedure, is now often omitted for classical Hodgkin’s lymphoma if a whole-body PET-CT scan is negative for bone involvement. However, it may still be necessary if the PET-CT results are unclear or for certain less common subtypes of the disease.