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Guiding diagnosis and treatment of a complex disease

Updated: December 2014
Published: March 2013

What are Malignant Lymphomas?

Malignant lymphomas are cancers of the cells of the immune system. They are relatively common and represent the sixth most common malignancy in the United States.

Although reported in statistical literature as one (malignant lymphoma) or two (Hodgkin lymphoma and non-Hodgkin lymphoma) diseases, the most recent World Health Organization Classification of Haematologic and Lymphoid Neoplasms lists 80 established and provisional lymphoma entities.1

What are the Clinical Findings that Suggest a Diagnosis of Lymphoma?

  • Enlarged lymph nodes
  • Enlarged spleen or liver
  • Mass (tumor) in an extranodal site
  • Blood involvement—lymphocytosis
  • Fever
  • Weight loss
  • Night sweats
  • Pruritis (itchiness)

What are the Tools to Diagnose and Classify Lymphomas?

Lymphomas are among the most complex diseases to recognize and diagnose because they are pathologically complex, with features that overlap with reactive and inflammatory conditions and other nonhematologic malignancies.

Criteria for lymphoma diagnosis rely on morphology and a variety of ancillary studies, including phenotype and genetic features.

All Cases

Clinical history

  • Anatomic distribution of disease
  • “B symptoms”
    • Enlarged lymph nodes
    • Fever > 100.4°F for 3 consecutive days
    • Weight loss >10% of body weight in 6 months
    • Night sweats
  • Microscopic examination
  • Flow cytometry
  • Immunohistochemistry
Some Cases
  • Chromosomes, lymphoid tissue
  • FISH
Rare Cases
Molecular genetics
  • T-cell receptor gene rearrangements
  • Immunoglobulin gene rearrangements


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  1. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Fourth edition. Edited by SH Swerdlow, E Campo, NL Harris, et al: Lyon, France, IARC Press, 2008

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