OverviewNon-Hodgkin's lymphomas (NHLs) are a heterogeneous group of lymphoproliferative disorders originating in B-, T-, or natural killer (NK) lymphocytes. In the United States, B-cell lymphomas represent 80% to 85% of all cases, with 15% to 20% being T-cell lymphomas; NK lymphomas are very rare. In 2009, an estimated 65,980 new cases of NHL will be diagnosed and 19,500 will die of the disease.1 NHL is the sixth leading site of new cancer cases among men and fifth among women, accounting for 4% to 5% of new cancer cases and 3% to 4% of cancer-related deaths. Non-Hodgkin's Lymphomas Clinical Practice Guidelines in OncologyKey Words NCCN Clinical Practice Guidelines, non-Hodgkin's lymphoma, chronic lymphocytic leukemia, follicular lymphoma, diffuse large B-cell lymphoma, mantle cell lymphoma, peripheral T-cell lymphoma, cutaneous T-cell lymphoma, mycosis fungoides, Sézary syndrome, marginal zone lymphoma, mucosaassociated lymphoid tissue lymphoma, diagnosis, treatment, hematopathology, immunohistochemistry, treatment guidelines, staging evaluation, lymphoma pathology (JNCCN 2010;8:288-334) NCCN Categories of Evidence and ConsensusCategory 1: The recommendation is based on high-level evidence (e.g., randomized controlled trials) and there is uniform NCCN consensus. Category 2A: The recommendation is based on lowerlevel evidence and there is uniform NCCN consensus. Category 2B: The recommendation is based on lowerlevel evidence and there is nonuniform NCCN consensus (but no major disagreement). Category 3: The recommendation is based on any level of evidence but reflects major disagreement. Please NoteThese guidelines are a statement of consensus of the authors regarding their views of currently accepted approaches to treatment. Any clinician seeking to apply or consult these guidelines is expected to use independent medical judgment in the context of individual clinical circumstances to determine any patient's care or treatment. The National Comprehensive Cancer Network makes no representation or warranties of any kind regarding their content, use, or application and disclaims any responsibility for their applications or use in any way.These guidelines are copyrighted by the National Comprehensive Cancer Network. All rights reserved. These guidelines and the illustrations herein may not be reproduced in any form without the express written permission of the NCCN © 2010. Disclosures for the NCCN Non-Hodgkin's Lymphomas Guidelines PanelAt the beginning of each NCCN guidelines panel meeting, panel members disclosed any financial support they have received from industry. Through 2008, this information was published in an aggregate statement in JNCCN and online. Furthering NCCN's commitment to public transparency, this disclosure process has now been expanded by listing all potential conflicts of interest respective to each individual expert panel member.Individual disclosures for the NCCN Non-Hodgkin's Lymphomas Guidelines Panel members can be found on page 334. (To view the most recent version of these guideli...