In the remaining ~30% of other cases, the disease begins as an extranodal lymphoma, most commonly in the stomach, or, less commonly, in other sites such as the testicles, breasts, uterus, ovaries, kidneys, adrenal glands, thyroid gland, or bone. The presenting signs and symptoms in these cases reflect the presence of a rapidly expanding tumor or infiltrate that produces symptoms specific to the organ of involvement such as increased size, pain, and/or dysfunction. Individuals with nodal or extranodal disease also present with: systemic B symptoms such as weight loss, night sweats, fevers, and/or fatigue in ~33% of cases; unexplained elevations in their blood levels of lactic acid dehydrogenase and beta-2 microglobulin in many cases; malignant cells infiltrating their bone marrow in 10–20% of cases; and/or localized Stage I or II disease in up to 50% of cases and disseminated Stage III or IV disease in the remaining cases. Bone marrow involvement may be due to DLBCL, NOS cells or low grade lymphoma cells; only DLBCL, NOS cell infiltrates indicate a worse prognosis. Uncommonly, DLBCL may arise as a transformation of marginal zone lymphoma (MZL) in individuals who have been diagnosed with this indolent cancer 4–5 years (median times) previously. Prognostic indicators based on clinical presentation
The International Prognostic Index and more recently, the Indexs age-adjusted variant use age >60 years, elevated serum lactate dehydrogenase levels, low performance status, and involvement in more than one extranodal site as contributors to a poor prognosis in patients with DLBCL, NOS.
Subtypes of diffuse large B-cell lymphoma
DLBCL subtypes have been sorted into groups based on their distinctive morphology or immunophenotype, distinctive clinical issues, and distinctive virus-driven etiology. The prognoses and treatment of these subtypes varies with their severity. Most subtypes are aggressive diseases and consequently treated in a manner similar to DLBCL,NOS. Further details on these subtypes, including their treatments, can be found in their respective main article linkages. DLBCL with a distinctive morphology or immunophenotype
T cell/histiocyte-rich large B-cell lymphoma
T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a DLBCL in which tumors containing small numbers of usually large neoplastic B-cells embedded in a background of reactive T-cells and histiocytes develop in the liver, spleen, bone marrow and/or, rarely other sites. Patients usually present with advanced disease; their overall 3 year survival rates in different studies range between 46% and 72%. ALK+ large B-cell lymphoma
ALK+ large B-cell lymphoma (ALK+ LBCL) is a DLBCL in which neoplastic lymphocytes that express the ALK tyrosine kinase receptor protein infiltrate lymph nodes as well as extranodal sites, e.g. the mediastinum, bones, bone marrow, nasopharynx, tongue, stomach, liver, spleen, and skin. About 60% of these individuals present with advanced disease. ALK+ LBCL has an overall 5 year survival rate of ~34%. Plasmablastic lymphoma
Plasmablastic lymphoma (PBL) is a DLBCL in which neoplastic immunoblastic or plasmablastic cells embedded in a background of other cell types infiltrate the oral/nasal cavity or much less often the gastrointestinal tract. Some 70% of individuals with PBL are infected with EBV and/or (particularly those with oral/nasal cavity disease) human immunodeficiency virus (HIV).