Acute monocytic leukemia with KMT2A::LASP1 developed 9 months after diagnosis of acute megakaryoblastic leukemia in a 2-year-old boy.

Abstract

Acute myeloid leukemia (AML) is known as one of the subsequent malignant neoplasms that can develop after cancer treatment, but it is difficult to distinguish from relapse when the preceding cancer is leukemia. We report a 2-year-old boy who developed acute megakaryoblastic leukemia (AMKL, French-American-British classification [FAB]: M7) at 18 months of age and achieved complete remission with multi-agent chemotherapy without hematopoietic stem cell transplantation. Nine months after diagnosis and 4 months after completing treatment for AMKL, he developed acute monocytic leukemia (AMoL) with the KMT2A::LASP1 chimeric gene (FAB: M5b). The second complete remission was achieved using multi-agent chemotherapy and he underwent cord blood transplantation 4 months after AMoL was diagnosed. He is currently alive and disease free at 39 and 48 months since his AMoL and AMKL diagnoses, respectively. Retrospective analysis revealed that the KMT2A::LASP1 chimeric gene was detected 4 months after diagnosis of AMKL. Common somatic mutations were not detected in AMKL or AMoL and no germline pathogenic variants were detected. Since the patient's AMoL was different from his primary leukemia of AMKL in terms of morphological, genomic, and molecular analysis, we concluded that he developed a subsequent leukemia rather than a relapse of his primary leukemia.

• Authors: Takashi Fujita, Hiroko Fukushima, Toru Nanmoku, Yuki Arakawa, Takao Deguchi, Ryoko Suzuki, Yuni Yamaki, Sho Hosaka, Hidetoshi Takada
• Journal: International journal of hematology (Int J Hematol) Vol. 118 Issue 4 Pg. 514-518 (Oct 2023) ISSN: 1865-3774 [Electronic] Japan
• PMID: 37314622 (Publication Type: Case Reports, Journal Article)
• Copyright: © 2023. Japanese Society of Hematology.

Chemical References

• Adaptor Proteins, Signal Transducing
• Cytoskeletal Proteins
• LASP1 protein, human
• LIM Domain Proteins
• KMT2A protein, human
• Histone-Lysine N-Methyltransferase
• Oncogene Proteins, Fusion

Topics

• Child, Preschool
• Humans
• Male
• Adaptor Proteins, Signal Transducing
• Cytoskeletal Proteins
• Leukemia, Megakaryoblastic, Acute (diagnosis, genetics, therapy)
• Leukemia, Monocytic, Acute (diagnosis, genetics, therapy)
• LIM Domain Proteins
• Recurrence
• Remission Induction
• Retrospective Studies
• Histone-Lysine N-Methyltransferase (genetics)
• Oncogene Proteins, Fusion (genetics)