The diagnosis of Hodgkin’s lymphoma, a cancer originating in the lymphatic system, relies on a structured, multi-step process. This cancer begins when lymphocytes, a type of white blood cell, start growing abnormally, often leading to swelling in the lymph nodes. Since many other conditions, such as common infections, can mimic the symptoms of this disease, testing is required. The purpose of this testing sequence is not only to confirm the presence of cancerous cells but also to determine the disease’s full extent within the body.
Initial Medical Evaluation
The diagnosis process starts with a thorough review of the patient’s medical history and a physical examination. A physician will ask about specific systemic indicators, often referred to as “B symptoms.” These include unexplained fever, drenching night sweats, and unintentional weight loss exceeding 10% of total body weight over six months. These symptoms, present in about 40% of patients, are significant factors in the disease assessment.
During the physical exam, the doctor systematically checks for enlarged lymph nodes in accessible areas like the neck (cervical), armpits (axillary), and groin (inguinal). Affected nodes are frequently painless, firm, and rubbery, distinguishing them from the tender swelling often seen with infection. The physician will also palpate the abdomen to check for enlargement of the spleen (splenomegaly) or the liver (hepatomegaly), which can indicate more extensive disease involvement. This initial assessment determines if the patient warrants further, more invasive testing.
Blood and Laboratory Analysis
Once suspicion is raised, several blood tests are ordered to look for abnormalities that often accompany the disease. A Complete Blood Count (CBC) measures the levels of red cells, white cells, and platelets. Abnormalities like mild anemia, caused by chronic inflammation, or low lymphocyte counts (lymphopenia) may be observed.
Other laboratory tests measure markers of inflammation and organ function. The Erythrocyte Sedimentation Rate (ESR) is often significantly elevated in active disease, serving as an important indicator and prognostic factor. Basic liver and kidney function tests are also conducted to assess baseline organ health. Elevated levels of Lactate Dehydrogenase (LDH) or low levels of serum albumin can correlate with a higher tumor burden and are considered important prognostic factors.
Advanced Imaging Scans
Imaging is used to locate all sites of potential disease throughout the body and determine the size and location of suspicious masses. The standard approach involves a Positron Emission Tomography (PET) scan combined with a Computed Tomography (CT) scan, known as a PET-CT. This combination is highly effective because it merges the anatomical detail of the CT scan with the metabolic activity mapping of the PET scan.
Before the PET scan, a radioactive sugar is injected into the patient, which cancer cells readily absorb due to their high metabolism. The PET-CT highlights these metabolically active areas, providing a comprehensive picture of all disease sites, including those outside of the main lymph node chains. This imaging is sensitive and can detect sites that a standard CT scan might miss. The results of the PET scan are often interpreted using a five-point scale called the Deauville score to assess the intensity of the tracer uptake.
Tissue Biopsy for Confirmation
The definitive diagnosis of Hodgkin’s lymphoma requires obtaining and analyzing a tissue sample through a biopsy. This procedure confirms the presence of the specific malignant cells characteristic of the disease. A specialized pathologist examines the tissue under a microscope to identify Reed-Sternberg cells, which are large, abnormal lymphocytes that signal Hodgkin’s lymphoma.
The preferred method is an excisional lymph node biopsy, where the surgeon removes the entire suspicious lymph node. Removing the whole node provides the pathologist with adequate tissue to confirm the diagnosis, determine the specific subtype, and perform necessary additional testing. Less-invasive procedures, such as core needle biopsy or fine-needle aspiration (FNA), often do not yield enough intact tissue for a conclusive diagnosis. If a needle biopsy is inconclusive but suspicion remains, an excisional biopsy is usually performed.
Immunohistochemistry is a technique performed on the biopsy sample to look for specific protein markers on the cell surface, such as CD15 and CD30. These markers are typically found on Reed-Sternberg cells in classic Hodgkin’s lymphoma. This specialized testing helps distinguish Hodgkin’s lymphoma from other types of lymphoma and other diseases that might cause lymph node swelling. The pathologist’s report detailing the cellular features and protein markers is the formal confirmation of the disease.
Assessing Disease Spread
After the diagnosis is confirmed by biopsy, additional tests determine the full extent of the cancer, a process known as staging. Staging uses the Ann Arbor system, which categorizes the disease based on the number of involved lymph node regions and spread to organs outside the lymphatic system. The results of advanced imaging scans, particularly the PET-CT, are fundamental to this process, as they map all the cancer sites.
A Bone Marrow Aspiration and Biopsy checks for the presence of lymphoma cells in the bone marrow. This procedure involves collecting small samples of liquid and solid bone marrow, typically from the hip bone, for microscopic analysis. However, studies have shown that PET-CT is highly sensitive in detecting bone marrow involvement, leading to the omission of the bone marrow biopsy in many patients who have a normal PET-CT scan. The final stage designation, which includes a modifier for the presence or absence of B symptoms, guides the selection of the most appropriate treatment plan.