γδ T-Cell Acute Lymphoblastic Leukemia/Lymphoma: Discussion of Two Pediatric Cases and Its Distinction from Other Mature γδ T-Cell Malignancies

Abstract

Gamma delta (γδ) T-cell antigen receptor (TCR) expression and its related T-cell differentiation are not commonly reported in T-cell acute lymphoblastic leukemia/lymphoma (T-ALL). Here we report two pediatric T-ALL cases and present their clinical features, histology, immunophenotypes, cytogenetics, and molecular diagnostic findings. The first patient is a two-year-old girl with leukocytosis, circulating lymphoblasts, and a cryptic insertion of a short-arm segment at 10p12 into the long-arm segment of 11q23 resulting in an MLL and AF10 fusion transcript, which may be the first reported in γδ T-ALL. She responded to the chemotherapy protocol poorly and had persistent diseases. Following an allogeneic bone marrow transplant, she went into remission. The second patient is an eleven-year-old boy with a normal white cell count, circulating blasts, and a normal karyotype, but without any immature cellular markers by flow cytometric analysis. He responded to the chemotherapy well and achieved a complete remission. These cases demonstrate the diverse phenotypic, cytogenetic, and molecular aspects of γδ T-ALL. Early T-precursor- (ETP-) ALL and their differential diagnosis from other mature γδ T-cell leukemia/lymphomas are also discussed.

A Challenging Case of Gamma Delta T-Cell Lymphoma with Precursor T-Cells and Marked Eosinophilia: A Case Report

“…The 2008 World Health Organization (WHO) classification acknowledged two major groups of γδ T-cell lymphoma: Hepatosplenic γδ T-cell lymphoma (HSγδTL) and Primary cutaneous gamma-delta TCL (PCγδTCL) [ 5 ]. The 2016 WHO classification of γδ T-cell lymphoma combined a few more subcategories: (1) Hepatosplenic γδ T-cell lymphoma (HSγδTL); (2) Primary cutaneous gamma-delta TCL (PCγδTCL); (3) Monomorphic epitheliotropic intestinal TCL (MEITL); (4) Gamma-delta large granular lymphocytic leukemias (γδT-LGL) [ 1 ].…”

Gamma-Delta T-Cell Acute Lymphoblastic Leukemia/Lymphoma: Immunophenotype of Three Adult Cases

“…There are four types of gamma-delta (γδ) T-cell neoplasms, namely, γδ T-cell acute lymphoblastic leukemia/lymphoma (T-ALL), skin and mucosal γδ T-cell lymphoma, hepatosplenic T-cell lymphoma, and γδ T-cell large granular lymphocytic leukemia [1][2][3][4]. The incidence of γδ T-ALL is low [1,2]. It is characterized by the expression of γδ T-cell antigen receptors (TCRs).…”

Flow Cytometric Pattern of TCRVδ Subtype Expression Rapidly Identifies γδT Cell Lymphoma

“…LGL leukemia, γδ-type T-LGL leukemia patients have more obvious thrombocytopenia, lower absolute neutrophil count, and higher CD4 and CD8 double-negative ratios (16). From the immunophenotype, γδT cell tumors often express CD2, CD3, CD7, CD56, and TCRγδ and do not express CD4, CD8, CD5, and TCRαβ (17,18). Reports on γδ type lymphoma are still rare and have not been thoroughly studied.…”