CBFA2T3::GLIS2‐positive acute leukemia with RAM and mixed T/megakaryocytic phenotype

• Published in: EJHaem Vol. 4; no. 3; pp. 765 - 769
• Main Authors: Khanlari, Mahsa, Wang, Lu, Bolen, Christine Y, Otanez, Felipe Sebastian Bautista, Furtado, Larissa V., Key, Laura, Irwin, Lisa, Wang, Wei, Klco, Jeffery M.
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01-08-2023; John Wiley and Sons Inc; Wiley
• Subjects: Acute lymphoblastic leukemia; acute megakaryoblast leukemia; Acute myeloid leukemia; Biopsy; Bone marrow; CBFA2T3; CD38 antigen; CD45 antigen; CD56 antigen; Differential diagnosis; Down's syndrome; Flow cytometry; Genotype & phenotype; GLIS2; Leukemia; Lymphatic leukemia; Lymphatic system; Lymphocytes T; Lymphoma; mixed phenotype acute leukemia; Morphology; Myelodysplastic syndrome; Phenotypes; Short Report; Short Reports; mixed phenotype acute leukemia; CBFA2T3; GLIS2; acute megakaryoblast leukemia
• ISSN: 2688-6146; 2688-6146
• DOI: 10.1002/jha2.741

Herein, we present a rare case of acute myeloid leukemia (AML) with CBFA2T3‐rearrangement and the expression of megakaryocytic and lymphoid markers, highlighting the need for a high suspicion index in differential diagnosis and applying adequate workup to avoid misdiagnosing this entity.
CBFA2T3::GLIS2‐positive AML is primarily found in infants with non‐down syndrome acute megakaryoblastic leukemia (non‐DSAMKL). Flow cytometry immunophenotyping plays an important role in recognizing the unique immunophenotype of bright CD56 expression with dim/negative expression of HLA‐DR, CD38, and CD45 termed the RAM immunophenotype in this entity. Still, CBFA2T3::GLIS2‐positive acute leukemia with T/megakaryocytic markers could be misdiagnosed as T‐lymphoblastic leukemia/lymphoma, early T‐cell precursor acute lymphoblastic leukemia/lymphoma, NK lymphoblastic leukemia, AML with minimal differentiation, or AML with myelodysplasia‐related changes.