Lymphoma Classification.

Area of Science:

• Hematology
• Oncology
• Pathology

Background:

• The Revised European American Classification of Lymphoid Neoplasms (REAL) established an integrative approach 25 years ago.
• This principle continues to guide the World Health Organization (WHO) classifications of hematopoietic tumors.
• The WHO classification has expanded to encompass a comprehensive understanding of lymphoid neoplasms.

Purpose of the Study:

• To review recent modifications and new data in the 2017 WHO classification of lymphoid neoplasms.
• To highlight the continued importance of an integrative approach in defining lymphoid cancers.
• To provide an overview of the updated classification of mature lymphoid neoplasms.

Main Methods:

• Review of the 2017 World Health Organization classification of tumors of the hematopoietic organs.
• Analysis of the parameters used for defining lymphoid neoplasms, including morphology, immunophenotype, and genetic/molecular profiles.
• Identification of newly recognized entities and modifications in classification.

Main Results:

• The 2017 WHO classification includes over 80 entities of mature lymphoid neoplasms (B-cell, T-cell, and Hodgkin lymphomas).
• The classification incorporates morphology, immunophenotype, genetic lesions, molecular profiles, clinical features, and cellular derivation for disease definition.
• Recognition of incipient and indolent lymphoid neoplasms with low progression potential is a key feature.

Conclusions:

• The integrative approach to lymphoid neoplasm classification remains a cornerstone, as exemplified by the 2017 WHO update.
• The 2017 classification provides a refined framework for diagnosing and understanding a wide spectrum of lymphoid malignancies.
• Continued research and updates are essential for accurately classifying these complex diseases.