Juvenile myelomonocytic leukemia with t(3;5)(q25;q35), Auer rods and marked myelodysplasia

• Published in: Pathology, research and practice Vol. 214; no. 6; pp. 919 - 923
• Main Authors: Li, Weijie, Cooley, Linda D., August, Keith
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 01.06.2018
• Subjects: 19q LOH; Auer rods; Juvenile myelomonocytic leukemia; Myelodysplasia; t(3;5); Juvenile myelomonocytic leukemia; Myelodysplasia; 19q LOH; Auer rods; t(3;5)
• ISSN: 0344-0338; 1618-0631
• DOI: 10.1016/j.prp.2017.11.024

Juvenile myelomonocytic leukemia (JMML) is a rare aggressive childhood leukemia characterized by an excess proliferation of cells of granulocytic and monocytic lineages. The WHO classifies JMML with the myelodysplastic/myeloproliferative neoplasms. Myelodysplasia in JMML is usually minimal to mild. Auer rods have never been reported in JMML. We present a 2-year-old boy with splenomegaly, leukocytosis, thrombocytopenia, anemia, and excess myeloblasts with easily seen Auer rods, and marked dysgranulopoiesis and dyserythropoiesis. Conventional cytogenetic analysis showed a sole abnormality of t(3;5)(q25;q35). Microarray analysis showed a terminal 21 Mb region of copy-neutral loss of heterozygosity on 19q. Disease-related somatic NRAS mutation was detected. This case represents an unusual JMML with Auer rods and marked myelodysplasia. These unusual histopathologic features may be related to the t(3;5)(q25;q35). A t(3;5) with variable breakpoints has been reported in a small proportion of acute myeloid leukemias and myelodysplastic syndromes. To our knowledge, this is the first JMML case reported with this translocation.