Updates in the Pathology of Precursor Lymphoid Neoplasms in the Revised Fourth Edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues

作者：Wenzinger Christopher; Williams Eli; Gru Alejandro A^*

来源：Current Hematologic Malignancy Reports, 2018, 13(4): 275-288.

DOI：10.1007/s11899-018-0456-8

• Lymphoblastic lymphoma
• ALL
• WHO revision
• Acute leukemia

Acute lymphoblastic leukemias (ALL) are malignant disorders of immature B or T cells that occur characteristically in children, usually under the age of 6 (75%). Approximately 6000 new cases of ALL are diagnosed each year in the USA, 80-85% of which represent B-ALL forms. Most presentations of B-ALL are leukemic, whereas T-ALL presents with a mediastinal mass, with or without leukemic involvement. The revised fourth edition of the World Health Organization (WHO) classification (2017) has introduced some changes in both B and T-ALL. Here, we summarize the categories of lymphoblastic leukemia/lymphomas as defined by the WHO and recent developments in the understanding of this group of hematologic malignancy.
Two provisional categories of B-ALL have now been identified including B-ALL, BCR-ABL1-like, and B-ALL with iAMP21. The Philadelphia chromosome-like B-ALL includes forms of the disease that shares the expression profiling of B-ALL with t(9;22) but lack such rearrangement. The second one shows amplification of part of the chromosome 21. Both entities are associated with worse prognosis. Within the T-ALL group, an early precursor T cell form has now been introduced as a provisional category. Such group demonstrates expression of stem cell and myeloid markers in conjunction with the T cell antigens.
The current review summarizes the recent updates to the WHO classification.

• 出版日期2018-8