Successful acute lymphoblastic leukemia‐type therapy in two children with mixed‐phenotype acute leukemia

• Published in: Pediatrics international Vol. 58; no. 10; pp. 1072 - 1076
• Main Authors: Otsubo, Keisuke, Yabe, Miharu, Yabe, Hiromasa, Fukumura, Akiko, Morimoto, Tsuyoshi, Kato, Masahiko, Mochizuki, Hiroyuki
• Format: Journal Article
• Language: English
• Published: Australia Blackwell Publishing Ltd 01.10.2016
• Subjects: 2008 World Health Organization classification; Acute Disease; Acute lymphoblastic leukemia; acute lymphoblastic leukemia‐type therapy; acute myeloblastic leukemia‐type therapy; Biopsy; Bone Marrow Cells - pathology; CD3 antigen; Child; Children; Classification; Combined Modality Therapy - methods; Female; Genotype & phenotype; Humans; Immunology; Leukemia; Lymphatic leukemia; Male; mixed phenotype; Patients; Pediatrics; Peroxidase; Phenotypes; Precursor Cell Lymphoblastic Leukemia-Lymphoma - diagnosis; Precursor Cell Lymphoblastic Leukemia-Lymphoma - therapy; Remission; Stem cell transplantation; Transplantation; Treatment Outcome; 2008 World Health Organization classification; mixed phenotype; acute myeloblastic leukemia-type therapy; acute lymphoblastic leukemia-type therapy
• ISSN: 1328-8067; 1442-200X
• DOI: 10.1111/ped.13045

Mixed‐phenotype acute leukemia (MPAL) is a rare type of leukemia expressing both myeloid and lymphoid markers. There is limited information, especially on pediatric cases. Therefore, the optimal therapeutic approach to pediatric MPAL has not been defined. Here, we report two pediatric cases of MPAL. According to the 2008 World Health Organization (WHO) classification and European Group for the Immunological Characterization of Leukemias (EGIL) criteria, patient 1 was diagnosed with overt MPAL positive for the myeloid marker myeloperoxidase (MPO), and B‐lymphoid markers. Patient 2 was diagnosed with T‐cell acute lymphoblastic leukemia (T‐ALL) using EGIL criteria. According to the 2008 WHO classification, however, patient 2 was diagnosed with overt MPAL positive for CD3, T‐lymphoid markers and MPO. We chose an ALL‐type therapy consisting of both lymphoid‐ and myeloid‐directed agents; these patients have maintained complete remission following treatment. Further information on pediatric MPAL is needed to establish an appropriate therapeutic strategy including stem cell transplantation for this rare condition.