B-CELL LYMPHOID NEOPLASMS IN THE 5TH EDITION OF THE WHO CLASSIFICATION OF HEMATOLYMPHOID TUMORS (2022). 1. General principles of classification. Precursor B-cell neoplasms

Abstract

Tumors of lymphoid and hematopoietic tissues are among the most prevalent malignancies. The tumors originating from lymphoid cells are of the utmost heterogeneity. The development of the generally accepted classifi ation sys- tem for this group of the malignancies became a priority task and its clinical implementation has been already advantageous. The in-depth insight into the pathogenesis of lymphoid neoplasms requires the continuous revision of the classification of these diseases. In 2022, World Health Organization specialists prepared the regular 5th issue of the Classification of Hematolymphoid Tumors representing a revision of the previous one (2017). The basic provisions of the new classification concerning B-cell lymphoid neoplasms are disclosed in this review composed of two parts. The review focuses on the principal changes as compared with the previous version of the classification. The first part of the review relates to two major categories such as tumor-like lesions with B-cell predominance and precursor B-cell neoplasms. The laboratory criteria important for the final diagnosis of the various nosological forms are discussed. Mature B-cell neoplasms, plasma cell neoplasms and other diseases with paraproteins will be presented in the next issue. the classification of these diseases. In 2022, World Health Organization specialists prepared the regular 5th issue of the Classification of Hematolymphoid Tumors representing a revision of the previous one (2017). The basic provisions of the new classification concerning B-cell lymphoid neoplasms are disclosed in this review composed of two parts. The review focuses on the principal changes as compared with the previous version of the classification. The first part of the review relates to two major categories such as tumor-like lesions with B-cell predominance and precursor B-cell neoplasms. The laboratory criteria important for the final diagnosis of the various nosological forms are discussed. Mature B-cell neoplasms, plasma cell neoplasms and other diseases with paraproteins will be presented in the next issue.