From the Guidelines
Diagnosing lymphoma requires a comprehensive approach involving multiple tests, with the definitive diagnosis made through a biopsy, preferably an excisional or incisional biopsy, as recommended by the most recent guidelines 1. The diagnostic criteria for lymphoma involve a combination of morphology, immunohistochemistry, and flow cytometry reviewed by an experienced lymphoma pathologist, as well as molecular studies to accurately categorize the lymphoma 1. Key steps in the diagnostic process include:
- A thorough physical examination to identify enlarged lymph nodes, spleen, or liver
- Collection of a detailed medical history
- Blood tests to check for abnormalities in blood cell counts and to assess organ function
- Imaging studies such as CT scans, PET scans, or MRIs to determine the extent of the disease
- Biopsy of an affected lymph node, with an excisional or incisional biopsy preferred over a fine-needle aspirate or core needle biopsy alone 1
- Additional specialized tests like immunohistochemistry, flow cytometry, and genetic testing on the biopsy sample to determine the specific type of lymphoma
- Bone marrow biopsy may also be necessary to check if the lymphoma has spread to the bone marrow, although this may not be required in all cases, such as when the PET scan is negative or displays a homogenous pattern of bone marrow uptake 1. The choice of diagnostic tests and procedures may vary depending on the specific type of lymphoma and the individual patient's circumstances, with the goal of developing an appropriate treatment plan that takes into account the patient's overall health and quality of life.
From the Research
Diagnostic Criteria for Lymphoma
The diagnostic criteria for lymphoma involve a combination of clinical presentation, imaging studies, and laboratory tests.
- Lymphoma typically presents as painless adenopathy, with systemic symptoms of fever, unexplained weight loss, and night sweats occurring in more advanced stages of the disease 2.
- An open lymph node biopsy is preferred for diagnosis 2.
- The Lugano classification system incorporates symptoms and the extent of the disease as shown on positron emission tomography/computed tomography (PET/CT) to stage lymphoma 2, 3.
Imaging Studies
- 18F-FDG PET/CT is the imaging modality of choice for the accurate initial staging of most lymphomas 3, 4.
- PET/CT has increased sensitivity in the detection of nodal involvement even in small or normal-sized nodes 3.
- It shows higher sensitivity than CT in the detection of extra-nodal disease, most often in the spleen and bone marrow 3.
Laboratory Tests
- Primary diagnosis and classification of lymphoma can be achieved with a variety of specimens 5, 6.
- The American Society for Clinical Pathology, the College of American Pathologists, and the American Society of Hematology have established evidence-based guidelines for the preanalytic phase of testing, focusing on specimen requirements for the diagnostic evaluation of lymphoma 5, 6.
- Disease prevalence in patient populations, availability of ancillary testing, and diagnostic goals should be incorporated into algorithms tailored to each practice environment 5, 6.
Staging and Treatment
- The Lugano classification system is used to stage lymphoma, which is then used to determine treatment 2.
- Treatment plans differ between the main subtypes of lymphoma, with non-Hodgkin lymphoma treated with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) with or without rituximab (R-CHOP), bendamustine, and lenalidomide, and Hodgkin lymphoma treated with combined chemotherapy with ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine), Stanford V, or BEACOPP with radiotherapy 2.