DLBCL, NOS represents 80–85% of all DLBCL. The remaining DLBCL cases consist of relatively rare subtypes that are distinguished by their morphology, (i.e. microscopic appearance), immunophenotype, (i.e. expression of certain marker proteins), clinical findings, and/or association with certain pathogenic viruses. Some cases of DLBCL, NOS, while not included in the 2016 World Health Organizations classification, are clearly associated with, and caused by, chronic infection by the bacterium, Helicobacter pylori. Diffuse large B-cell lymphoma, not otherwise specified
DLBCL cases that do not fit the distinctive clinical presentation, tissue morphology, neoplastic cell phenotype, and/or pathogen-associated criteria of other DLBCL subtypes are termed Diffuse large B-cell lymphoma, not otherwise specified: DLBCL, NOS, while representing 80–85% of all DLBCL cases, is a diagnosis of exclusion. In general, DLBCL, NOS is an aggressive disease with an overall long-term survival rate in patients treated with standard chemotherapy regimens of ~65%. However, this disease has many variants that differ not only in the just cited parameters but also in their aggressiveness and responsiveness to treatment. Presenting signs and symptoms
About 70% of DLBCL, NOS cases present primarily with lymph node disease. In these cases, the most typical presenting symptom at the time of diagnosis is a mass that is rapidly enlarging and located in a part of the body with multiple lymph nodes such as the groin, arm pits, or neck.
See also
Germinal center B-cell like diffuse large B-cell lymphoma

References
Sources
Swerdlow SH, Campo E, Jaffe ES, Pileri SA, eds. (2008). WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon: IARC. ISBN 978-92-832-2431-0. Goldman L, Schafer AI (2012). Goldmans Cecil Medicine (24th ed.). ISBN 978-1-4377-1604-7. Turgeon ML (2005). Clinical hematology: theory and procedures. Hagerstown, MD: Lippincott Williams & Wilkins. ISBN 978-0-7817-5007-3. == External links ==