ABSTRACT
We present a 23-year-old man with chronic neutrophilic leukemia (CNL). Physical examination revealed hepatosplenomegaly. Leukocytosis was evident with predominance of mature neutrophils with basophilic granules. Bone marrow aspiration revealed mature myeloid hyperplasia. Congenital Robertsonian translocation [45,XY,der(13;22)(q10;q10), in all of analyzed 20 cells] was detected; however, cytogenetic and molecular studies for 9:22 translocation were negative. He was diagnosed with CNL and hydroxyurea was started to control his symptoms and white blood cell count. He was then successfully treated with allogeneic bone marrow transplantation (BMT). Although the prognosis of CNL was not determined, curative therapy including allogeneic hematopoietic stem cell transplantation should be attempted in young patients with CNL.
Subject(s)
Bone Marrow Transplantation , Chromosome Disorders/genetics , Chromosomes, Human, Pair 13/ultrastructure , Chromosomes, Human, Pair 22/ultrastructure , Leukemia, Neutrophilic, Chronic/surgery , Translocation, Genetic , Cell Transformation, Neoplastic/genetics , Chromosomes, Human, Pair 13/genetics , Chromosomes, Human, Pair 22/genetics , Combined Modality Therapy , Cytotoxins/therapeutic use , Humans , Hydroxyurea/therapeutic use , Karyotyping , Leukemia, Neutrophilic, Chronic/drug therapy , Leukemia, Neutrophilic, Chronic/genetics , Male , Remission Induction , Transplantation Conditioning , Transplantation, Homologous , Young AdultABSTRACT
Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative disorder characterized by a proliferation mainly of mature neutrophils. The prognosis is generally poor and an optimal therapeutic strategy remains to be determined. Allogeneic hematopoietic stem cell transplantation (HSCT) is expected to be the only curative therapy so far. We report a 46-year-old male with progressive CNL who underwent bone marrow transplantation from an HLA-matched unrelated donor. After engraftment was achieved on day 35, relapse of CNL was confirmed on day 50. The progression of CNL was very rapid afterward and infiltration to the central nervous system was observed. The Janus Kinase 2 (JAK2) V617F homozygous mutation was detected from the peripheral blood or bone marrow samples throughout the clinical course. From comparison with reports of successful HSCT for CNL in the literature, it was inferred that HSCT should be performed in a stable status before progression. Furthermore, JAK2 V617F-positive CNL may contain an aggressive disease entity in contrast to previous reports. Accumulation of experiences is required to establish a definite role of HSCT in the treatment of CNL and a prognostic significance of JAK2 mutation in CNL.
