hematology and oncology
Non Hodgkin Lymphomas
Diagnosis of Non Hodgkin Lymphomas
Lymph node biopsy Often unilateral bone marrow aspiration and biopsy FDG-PET/CT of chest, abdomen, and pelvis for staging MRI of brain and/or spinal cord if neurologic symptoms are present As with Hodgkin lymphoma, non-Hodgkin lymphoma is usually suspected in patients with Painless lymphadenopathy Adenopathy detected on a chest x-ray or CT done for other reasons Painless lymphadenopathy can also result from Infectious Mononucleosis , Similar chest x-ray findings can result from Lung Carcinoma , Less commonly, patients present after a finding of peripheral lymphocytosis on a complete blood count (CBC) done for nonspecific symptoms. In such cases, the differential diagnosis includes Overview of Leukemia , Tests needed to make the diagnosis are followed by tests to complete staging and assess etiology and prognosis ( Diagnosis reference ). Enlarged lymph nodes are biopsied. If a node is palpable, no imaging is required initially, although CT or ultrasonography may be needed to properly plan subsequent tests. If the lesion is easily palpable, an open biopsy is preferred. If the lesion is in the lung or abdomen, a core needle biopsy (18- to 20-gauge needle) done using CT or ultrasound guidance can often obtain an adequate specimen for diagnosis. A fine needle biopsy (percutaneous or bronchoscopic) frequently will not produce adequate tissue, especially for initial diagnosis; core biopsy is preferred if deemed safe. Biopsies should be reviewed by a pathologist with expertise in lymphoma diagnosis so that the lymphoma can be correctly classified. If this review is not available locally, the slides should be sent to a reference laboratory with hematopathology expertise. The proper classification of non-Hodgkin lymphoma is critical for treatment planning. Non-Hodgkin lymphomas are potentially curable, but without a precise diagnosis, optimal therapy may not be chosen. Histologic criteria on biopsy include destruction of normal lymph node architecture and invasion of the capsule and adjacent fat by characteristic neoplastic cells. Immunophenotyping studies to determine the cell of origin are of great value in identifying specific subtypes and helping define prognosis and management; these studies also can be done on peripheral cells if they are present, but typically these stains are applied to formalin-fixed, paraffin-embedded tissue. Demonstration of the leukocyte common antigen CD45 by immunoperoxidase rules out metastatic cancer, which is often in the differential diagnosis of “undifferentiated” cancers. The test for leukocyte common antigen, most surface marker studies, and gene rearrangement (to document B-cell or T-cell clonality) can be done on fixed tissues. Cytogenetics and flow cytometry require fresh tissue. Once the diagnosis of lymphoma is made, staging tests are done. A combined fluorodeoxyglucose (FDG)-PET/CT scan of the chest, abdomen, and pelvis is recommended. PET/CT provides accurate location of lesions, their size (from CT) and tumor metabolism (from FDG-PET). If combined FDG-PET/CT is not available, a contrast-enhanced CT scan of the chest, abdomen, and pelvis is done. Unilateral bone marrow aspiration and biopsy is often done in patients with non-Hodgkin lymphoma. Bone marrow assessment in low-grade (indolent) non-Hodgkin lymphoma or T-cell non-Hodgkin lymphoma can be limited to cases where findings will change management or are needed to assess cytopenias. Blood tests typically include complete blood count with white blood cell differential, kidney function and liver tests (including serum creatinine, bilirubin, calcium, aspartate aminotransferase,albumin, alkaline phosphatase, and lactate dehydrogenase), uric acid, beta-2 microglobulin, andvitamin Dlevels. Serum protein electrophoresis with IgG, IgA, and IgM immunoglobulin levels are also done. Other tests are done depending on findings (eg, MRI of brain and/or spinal cord for neurologic symptoms). If uric acid levels are high, serum glucose-6-phosphate dehydrogenase (G6PD) level is checked because Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency precludes treatment with Patients with non-Hodgkin lymphoma are initially screened for Human Immunodeficiency Virus (HIV) Infection and After diagnosis, stage is determined to guide therapy. The commonly used Lugano staging system (see table Lugano Staging of Hodgkin Lymphoma and Non-Hodgkin Lymphoma ) incorporates Symptoms Physical examination findings Results of imaging tests, including CT of the chest, abdomen, and pelvis, and functional imaging with FDG-PET Bone marrow biopsy (in selected cases) Although stage I non-Hodgkin lymphoma does occur, the disease is typically disseminated when first recognized. 1.Cheson BD, Fisher RI, Barrington SF, et al: Recommendations for initial evaluation, staging, and response assessment of Hodgkin and non-Hodgkin lymphoma: The Lugano classification.J Clin Oncol32(27):3059-3068, 2014. 