If a physician suspects lymphoma based upon initial patient presentation, a more in-depth evaluation can help confirm the diagnosis and identify the type of lymphoma the patient has. A complete history and physical examination are necessary to determine the presence of painless, swollen lymph nodes (which is a prominent feature in many lymphoma cases) and extent of disease (Glass 2008; Sisson 2013).
Achieving an accurate diagnosis is crucial because just as the biological properties of the different subtypes of NHL differ, so do the treatment approaches that are likely to be most successful (Kobrinsky 2012; Leukemia & Lymphoma Society 2011a).
Diagnosis of lymphoma may involve a number of clinical and laboratory tests, including (Kobrinsky 2012; Leukemia & Lymphoma Society 2011a; Even-Sapir 2003):
- a thorough medical history evaluation
- physical examination
- imaging studies (eg, computed tomography [CT] and positron emission tomography [PET] and gallium scans)
- tissue biopsy
- blood tests such as complete blood count (CBC), chemistry panel, and erythrocyte sedimentation rate (ESR), serum lactate dehydrogenase, and beta 2-microglobulin
- laboratory techniques such as immunohistochemistry, flow cytometry, and genetic analysis
- assessment for infection (eg, H. pylori in suspected gastric MALT lymphoma)
Differentiating a benign (non-cancerous) tumor from a cancerous tumor can be complex because cancerous cells in many lymphomas closely resemble benign cells. Whenever a diagnosis of lymphoma is suspected, a biopsy of the largest and most accessible involved lymph node should be performed (Kobrinksy 2012; Portlock 2012). A biopsy involves taking a sample of the affected lymph node and sending it for microscopic evaluation by a pathologist. This allows molecular techniques to be performed to determine the cell of origin and delineate the best treatment approach (Ramsay 2013; Troxell 2005).