From the Guidelines
Diagnosing lymphoma requires a comprehensive approach, starting with a thorough medical history and physical examination, followed by blood tests, and ultimately, a biopsy, with excisional biopsy being the preferred method for accurate diagnosis, as recommended by the most recent guidelines 1. The diagnostic process for lymphoma involves several key steps, including:
- A thorough medical history and physical examination to identify symptoms such as persistent swollen lymph nodes, unexplained fever, night sweats, and weight loss.
- Blood tests to check for abnormalities in blood cell counts and to assess organ function.
- A biopsy, which can be done through a needle biopsy, but excisional biopsy is often preferred for more accurate results 1.
- A pathologist examines the tissue under a microscope and performs specialized tests like immunohistochemistry, flow cytometry, and molecular studies to determine the specific type of lymphoma.
- Once lymphoma is confirmed, imaging tests such as CT scans, PET scans, or MRIs are used to determine the stage of the disease 1.
- In some cases, a bone marrow biopsy may be necessary to check if lymphoma has spread to the bone marrow, although a PET-CT can sometimes replace the need for a bone marrow biopsy 1.
- Additional tests like lumbar puncture might be needed if there's concern about central nervous system involvement. This comprehensive diagnostic approach helps doctors determine the exact type and stage of lymphoma, which is crucial for developing an effective treatment plan, with the goal of minimizing morbidity, mortality, and improving quality of life 1.
From the Research
Diagnosing Lymphoma
To diagnose lymphoma, several steps are involved:
- An open lymph node biopsy is preferred for diagnosis 2
- Imaging tests such as positron emission tomography/computed tomography (PET/CT) are used to stage the disease and determine the extent of the disease 2, 3, 4, 5, 6
- The Lugano classification system incorporates symptoms and the extent of the disease as shown on PET/CT to stage lymphoma 2
- FDG-PET/CT is the current state-of-the-art imaging in lymphoma and plays a central role in treatment decisions 4, 5, 6
Imaging Tests
Imaging tests play a major role in diagnosis, staging, and response assessment of Hodgkin lymphoma and non-Hodgkin lymphoma:
- FDG-PET/CT provides information on bone marrow involvement and identifies all nodal, solid organ, cortical bone, and bone marrow disease 3
- MRI elucidates details of cortical bone and confirmation of bone marrow involvement 3
- Cross-sectional imaging has replaced staging laparotomy and splenectomy by demonstrating abdominal nodal groups and organ involvement 3
Staging Systems
Different staging systems are used for Hodgkin lymphoma and non-Hodgkin lymphoma:
- The Ann Arbor system with Cotswald modifications is used for Hodgkin lymphoma 3
- The St. Jude Classification by Murphy or the revised International Pediatric Non-Hodgkin Lymphoma Staging System (IPNHLSS) is used for non-Hodgkin lymphoma 3
- The Lugano classification system is used to stage lymphoma and determine treatment 2
Response Assessment
Response assessment is crucial in lymphoma management:
- FDG-PET/CT response is predictive of outcome and may identify a subgroup who benefit from consolidative radiotherapy 4
- PET-based response criteria (using five-point Deauville Score) are uniformly applied in FDG-avid lymphomas 6
- Quantitative PET metrics such as standardized uptake value (SUV), metabolic tumor volume, and total lesion glycolysis are being investigated as more reproducible and accurate predictors of response and prognosis 5