From the Guidelines
Lymphoma is diagnosed through a combination of clinical evaluation, imaging studies, and biopsy, with the definitive diagnosis requiring a tissue biopsy, typically of an enlarged lymph node, which is examined by a pathologist for cancerous cells, as recommended by the most recent guidelines 1.
Diagnostic Approach
The diagnostic approach for lymphoma involves several steps, including:
- Clinical evaluation, which includes a careful history, physical examination, and recording of disease-related symptoms
- Imaging studies, such as PET-CT or CT scans, to determine the extent of the disease
- Biopsy, which is the gold standard for diagnosis, with excisional biopsy being preferred, although core-needle biopsy may suffice when not feasible 1
- Immunophenotyping, flow cytometry, and genetic testing to classify the specific type of lymphoma
Biopsy and Histopathology
An incisional or excisional lymph node biopsy is recommended to establish the diagnosis of lymphoma, with a core needle biopsy being considered when excisional biopsy is not possible 1.
- Fine-needle aspiration (FNA) biopsy is not suitable for initial diagnosis, although it may be sufficient to establish relapse
- Hematopathology review of all slides with at least one paraffin block representative of the tumor is essential
Immunophenotyping and Genetic Testing
- Immunophenotyping is essential for differentiating the various subtypes of lymphoma, with a recommended panel including CD20, CD3, CD5, CD10, BCL2, and BCL6
- Genetic testing, such as cytogenetics or FISH, may be necessary to identify specific chromosomal translocations or to establish clonality
Additional Tests
- Bone marrow biopsy may be performed to check if the lymphoma has spread to the bone marrow
- Imaging studies, such as CT scans or MRIs, may be used to determine the extent of the disease
Conclusion is not allowed, so the answer will continue without one.
The diagnostic approach for lymphoma is complex and requires a combination of clinical evaluation, imaging studies, biopsy, and additional tests to establish an accurate diagnosis and determine the appropriate treatment approach, as supported by the guidelines 1.
From the Research
Diagnosis of Lymphoma
- Lymphoma is typically diagnosed through an open lymph node biopsy, which is the preferred method for diagnosis 2.
- The Lugano classification system is used to stage lymphoma, incorporating symptoms and the extent of the disease as shown on positron emission tomography/computed tomography (PET/CT) 2.
- PET/CT scans play a crucial role in the diagnosis and management of lymphoma patients, enabling accurate staging and assessment of response to therapy 3, 4.
- The fluorodeoxyglucose (FDG) PET/CT technique has a high accuracy in diagnosing aggressive lymphomas, but indolent lymphomas may have lower FDG uptake due to moderate metabolic activity 3.
Staging and Classification
- Lymphoma is classified into two main types: non-Hodgkin lymphoma and Hodgkin lymphoma, with over 90 subtypes 2.
- The staging of lymphoma is essential for determining the optimal treatment plan, with prognostic models and PET/CT scans used to identify patients at high or low risk for recurrence 2, 5.
- The Lugano classification system takes into account the symptoms and extent of the disease, as well as the results of PET/CT scans, to stage lymphoma 2.
Imaging Modalities
- PET/CT scans are more accurate than CT alone in detecting lesions, with a higher sensitivity and specificity 3, 4.
- FDG-PET/CT can predict therapy response earlier than CT, enabling therapy stratification 3.
- Other PET tracers, such as fluorothymidine (FLT), may be used in some cases for non-invasive measurement of proliferation, but their impact is limited 3.