hematology interest group cnl myeloproliferative neoplasm

 Hematology​ ​Interest​ ​Group  Myeloproliferative​ ​Neoplasm   October​ ​20,​ ​2017  Chronic​ ​Neutrophilic​ ​Leukemia    Clinical​ ​History  A​ ​65-year-old​ ​male​ ​presents​ ​for​ ​further​ ​evaluation​ ​of​ ​diffuse​ ​bone​ ​pain,​ ​abdominal​ ​discomfort,​ ​and  progressive​ ​fatigue​ ​for​ ​the​ ​last​ ​several​ ​months.​ ​ ​Examination​ ​reveals​ ​splenomegaly.​ ​ ​Laboratory  evaluation​ ​reveals​ ​a​ ​leukocyte​ ​count​ ​of​ ​76,900/uL​ ​(76.9​ ​x​ ​10​9​/L),​ ​hemoglobin​ ​11.8​ ​g/dL​ ​(118​ ​g/L),​ ​and  platelet​ ​count​ ​of​ ​91,000/uL​ ​(91​ ​x​ ​10​9​/L).​ ​ ​Bone​ ​marrow​ ​aspiration​ ​and​ ​biopsy​ ​revealed​ ​hypercellular​ ​bone  marrow,​ ​less​ ​than​ ​5%​ ​blasts,​ ​and​ ​no​ ​evidence​ ​of​ ​dysplasia.​ ​ ​Testing​ ​for​ ​BCR-ABL​ ​rearrangement​ ​and​ ​JAK2  V617F​ ​mutation​ ​was​ ​negative.         1      Laboratory​ ​Results    Hemogram  Patient’s​ ​Results  Reference​ ​Range  Hemoglobin​ ​(HgB)  11.8​ ​g/dL​ ​ ​(118​ ​g/L)  12-16​ ​g/​ ​dL​ ​ ​ ​(120​ ​160​ ​g/L)  RDW  17.2​ ​%  37-47%  Mean​ ​Corpuscular​ ​Volume​ ​(MCV)  91​ ​ ​fl  80-100​ ​fl  Platelets  91​ ​x​ ​10​9​/L  140-440​ ​x​ ​10​9​/L  White​ ​Blood​ ​Cell​ ​Count​ ​(WBC)  76.9​ ​x10​9​/L  4.8-10.8​ ​x10​9​/L    Peripheral​ ​Blood​ ​Smear  Three​ ​peripheral​ ​blood​ ​static​ ​images​ ​are​ ​shown:      2          Peripheral​ ​Blood  The​ ​peripheral​ ​blood​ ​film​ ​shows​ ​marked​ ​leukocytosis,​ ​a​ ​mild​ ​anemia,​ ​ ​and​ ​a​ ​decreased​ ​platelet​ ​ ​count.  Marked​ ​leukocytosis​ ​consisting​ ​mostly​ ​of​ ​increased​ ​numbers​ ​of​ ​mature​ ​neutrophils​ ​and​ ​bands​ ​with​ ​a  slight​ ​left-shift.​ ​There​ ​is​ ​no​ ​eosinophilia​ ​or​ ​basophilia.​ ​Toxic​ ​granulation​ ​of​ ​the​ ​neutrophils​ ​and​ ​occasional  granulocyte​ ​precursor​ ​containing​ ​Dohle​ ​Bodies​ ​are​ ​seen.​ ​No​ ​circulating​ ​myeloblasts​ ​or​ ​neutrophil  dysplasia​ ​seen.      3      Differential    ​ ​Differential  Patient’s​ ​Results  Reference​ ​Range  Neutrophils  47.3​ ​x10​9​/L    2.0-7.0​ ​x​ ​10​9​/L  Bands  22.3​ ​x10​9​/L  Lymphocytes  4.23​ ​ ​x10​9​/L  1.0-3.0​ ​x​ ​10​9​/L  Monocytes  0.38​ ​x10​9​/L  0.2-1.0x​ ​10​9​/L  Eosinophils  0.00​ ​x10​9​/L  0.02-0.5x​ ​10​9​/L  Basophils  0.00​ ​x10​9​/L  0.02-0.1x​ ​10​9​/L  Metamyelocytes  1.92​ ​ ​x10​9​/L  0.00-0.00x​ ​10​9​/L  Myelocytes  0.77​ ​x10​9​/L   0.00-0.00x​ ​10​9​/L  Reticulocyte​ ​Count   158​ ​x​ ​10​9​/L  10​ ​-​ ​90​ ​x​ ​10​9​/L  Bone​ ​Marrow    4          5        This​ ​bone​ ​marrow​ ​core​ ​biopsy​ ​shows​ ​the​ ​classic​ ​granulocytic​ ​predominance​ ​and​ ​hypercellularity.​ ​Megakaryocyte  morphology​ ​is​ ​normal.    6      Bone​ ​Marrow​ ​Biopsy​ ​and​ ​Aspirate  Both​ ​biopsy​ ​and​ ​aspirate​ ​are​ ​of​ ​good​ ​quality.​ ​Cellularity​ ​is​ ​90​ ​%.​ ​ME​ ​ratio​ ​is​ ​increased​ ​(M/E​ ​ratio=​ ​10:1).  Granulopoiesis​ ​is​ ​hyperplastic,​ ​shows​ ​healthy​ ​granulation​ ​and​ ​left-shift.​ ​.​ ​There​ ​is​ ​no​ ​increase​ ​in​ ​blast  cells.​ ​ ​No​ ​eosinophilia​ ​or​ ​basophilia.​ ​ ​Erythropoiesis​ ​is​ ​reduced​ ​but​ ​appears​ ​normoblastic.  Megakaryocytes​ ​are​ ​present​ ​but​ ​there​ ​is​ ​no​ ​crowding.​ ​ ​The​ ​biopsy​ ​does​ ​not​ ​show​ ​any​ ​streaming​ ​pattern.  The​ ​trabecular​ ​bone​ ​is​ ​unremarkable.​ ​ ​The​ ​lymphoplasmacytic​ ​complement​ ​is​ ​unremarkable.     Bone​ ​Marrow​ ​Differential​ ​(500​ ​Cells​ ​Counted)    Neutrophils​ ​ ​ ​ ​15%   Late​ ​normoblasts​ ​ ​ ​ ​ ​ ​ ​ ​ ​5%   Plasma​ ​cells​ ​ ​0%  Bands​ ​ ​ ​ ​ ​32%  Intermediate​ ​normoblasts​ ​1%  ​ ​ ​Lymphocytes​ ​ ​ ​3%  Metamyelocytes​ ​23%  ​ ​Early​ ​normoblasts​ ​ ​ ​ ​ ​ ​ ​ ​0%  ​ ​Monocytes​ ​ ​ ​ ​ ​0%  Myelocytes​ ​ ​ ​ ​20%  Proerythroblasts​ ​ ​ ​ ​ ​ ​ ​ ​ ​0%   ​ ​Eosinophils​ ​ ​ ​0%  Promyelocytes​ ​1​ ​%    Basophils​ ​ ​ ​ ​ ​0%  Blasts​ ​ ​ ​ ​ ​ ​ ​ ​0%  Cytogenetics   Normal​ ​Male​ ​Karyotype    Chromosome​ ​Abnormalities   CSF3R​ ​mutation​ ​by​ ​PCR-based​ ​DNA​ ​Sanger​ ​sequencing​ ​for​ ​exons​ ​14​ ​and​ ​17​ ​was​ ​performed​ ​on​ ​the​ ​bone  marrow​ ​aspirate.​ ​The​ ​following​ ​mutation​ ​was​ ​detected​ ​and​ ​translates​ ​into​ ​the​ ​following​ ​predicted​ ​protein  change:​ ​ ​p.T618I.   Diagnosis   Chronic​ ​Neutrophilic​ ​Leukemia     7      Discussion       Clinical​ ​findings:  Chronic​ ​neutrophilic​ ​leukemia​ ​(CNL)​ ​is​ ​a​ ​BCR/ABL-negative​ ​myeloproliferative​ ​neoplasm​ ​characterized​ ​by  a​ ​high​ ​number​ ​of​ ​mature​ ​neutrophils​ ​in​ ​the​ ​peripheral​ ​blood​ ​and​ ​a​ ​hyperplastic​ ​bone​ ​marrow.​ ​ ​CNL​ ​is  primarily​ ​a​ ​disease​ ​of​ ​adults​ ​and​ ​is​ ​generally​ ​diagnosed​ ​in​ ​the​ ​6th​ ​decade​ ​of​ ​life​ ​with​ ​a​ ​slight  predominance​ ​of​ ​males​ ​over​ ​females.​ ​ ​Symptoms​ ​include​ ​weight​ ​loss,​ ​easy​ ​bruising,​ ​bone​ ​pain,​ ​night  sweats,​ ​mucosal​ ​bleeding,​ ​and​ ​hepatosplenomegaly.    ​ ​At​ ​diagnosis​ ​the​ ​majority​ ​of​ ​patients​ ​have​ ​a​ ​mild​ ​normochromic​ ​normocytic​ ​anemia​ ​(median​ ​hemoglobin  11​ ​g/dl),​ ​the​ ​platelet​ ​count​ ​is​ ​variable.​ ​Peripheral​ ​blood​ ​shows​ ​a​ ​leukocytosis​ ​with​ ​an​ ​average​ ​WBC​ ​of  39×10​9​/L​ ​(​WBC​ ​WHO​ ​criteria​ ​>25×109​ ​/L​)​ ​that​ ​primarily​ ​consists​ ​of​ ​mature​ ​granulocytes.​ ​Segmented​ ​and  bands​ ​account​ ​for​ ​>​ ​80%​ ​of​ ​the​ ​total​ ​WBC​ ​and​ ​frequently​ ​show​ ​toxic​ ​granulation​ ​and​ ​dohle​ ​bodies.​ ​There  is​ ​no​ ​increase​ ​in​ ​monocytes,​ ​eosinophils,​ ​basophils,​ ​myelocytes,​ ​metamyelocytes,​ ​or​ ​myeloblasts.​ ​ ​No  granulocytic​ ​dysplasia​ ​is​ ​evident.  CNL​ ​diagnosis​ ​had​ ​remained​ ​primarily​ ​one​ ​of​ ​exclusion​ ​until​ ​the​ ​discovery​ ​of​ ​oncogenic​ ​mutations​ ​in​ ​the  colony-stimulating​ ​factor​ ​3​ ​receptor​ ​gene​ ​(CSF3R).​ ​ ​Mutations​ ​in​ ​CSF3R​ ​activate​ ​the​ ​receptor,​ ​leading​ ​to  the​ ​proliferation​ ​and​ ​differentiation​ ​of​ ​granulocytic​ ​precursors​ ​into​ ​mature​ ​segmented​ ​neutrophils,the  hallmark​ ​feature​ ​of​ ​CNL.​ ​This​ ​breakthrough​ ​discovery,​ ​which​ ​was​ ​made​ ​recently​ ​ ​in​ ​2013,​ ​provided​ ​a  molecular​ ​pathogenesis​ ​and​ ​phenotypic​ ​characterization​ ​facilitating​ ​an​ ​accurate​ ​and​ ​specific​ ​diagnosis​ ​of  CNL.​ ​ ​In​ ​2016​ ​the​ ​World​ ​Health​ ​Organization​ ​diagnostic​ ​guidelines​ ​for​ ​CNL​ ​were​ ​updated​ ​to​ ​include​ ​the  various​ ​CSF3R​ ​mutations.  Additional​ ​clinicopathologic​ ​characteristics​ ​of​ ​CNL​ ​include:   ● Hyperuricemia​ ​-​ ​A​ ​reflection​ ​of​ ​high​ ​bone​ ​marrow​ ​cellular​ ​turnover.  ● Elevated​ ​lactate​ ​dehydrogenase—LDH​ ​is​ ​an​ ​enzyme​ ​found​ ​in​ ​all​ ​normal​ ​and​ ​abnormal​ ​cells.​ ​It​ ​is  released​ ​from​ ​cells​ ​into​ ​the​ ​blood​ ​and​ ​is​ ​associated​ ​with​ ​energy​ ​production.   ● Elevated​ ​vitamin​​ ​B12–binding​ ​protein​ ​-​ ​Synthesized​ ​by​ ​the​ ​granulocytes,​ ​reflecting​ ​the​ ​degree​ ​of  leukocytosis.   ● Mild​ ​anemia​ ​-​ ​Hemoglobin​ ​level​ ​about​ ​11g/dl​ ​(110​ ​g/L)  ● Elevated​ ​leukocyte​ ​alkaline​ ​phosphatase​ ​(LAP)​ ​levels—​ ​Enzyme​ ​found​ ​in​ ​white​ ​blood​ ​cells.          8      World​ ​Health​ ​Organization​ ​(WHO),​ ​as​ ​of​ ​2016,​ ​the​ ​diagnostic​ ​criteria​ ​for​ ​CNL​ ​are​ ​the​ ​following:   1.​ ​PB​ ​WBC​ ​≥25​ ​×​ ​109/L   ​ ​ ​ ​ ​ ​Segmented​ ​neutrophils​ ​plus​ ​band​ ​forms​ ​≥80%​ ​of​ ​WBCs   ​ ​ ​ ​ ​ ​Neutrophil​ ​precursors​ ​(promyelocytes,​ ​myelocytes,​ ​and​ ​metamyelocytes)​ ​<10%​ ​of​ ​WBC   ​ ​ ​ ​ ​ ​Myeloblasts​ ​rarely​ ​observed   ​ ​ ​ ​ ​ ​Monocyte​ ​count​ ​<1​ ​×​ ​109/L   ​ ​ ​ ​ ​ ​No​ ​dysgranulopoiesis  2.​ ​Hypercellular​ ​BM   ​ ​ ​ ​ ​ ​Neutrophil​ ​granulocytes​ ​increased​ ​in​ ​percentage​ ​and​ ​number   ​ ​ ​ ​ ​ ​Neutrophil​ ​maturation​ ​appears​ ​normal   ​ ​ ​ ​ ​ ​Myeloblasts​ ​<5%​ ​of​ ​nucleated​ ​cells  3.​ ​Not​ ​meeting​ ​WHO​ ​criteria​ ​for​ ​BCR-ABL1​+​ ​CML,​ ​PV,​ ​ET,​ ​or​ ​PMF  4.​ ​No​ ​rearrangement​ ​of​ ​PDGFRA​,​ ​PDGFRB​,​ ​or​ ​FGFR1​,​ ​or​ ​PCM1-JAK2  5.​ ​Presence​ ​of​ ​CSF3R​ ​T618I​ ​or​ ​other​ ​activating​ ​CSF3R​ ​mutation  or  In​ ​the​ ​absence​ ​of​ ​a​ ​CSFR3R​ ​mutation,​ ​persistent​ ​neutrophilia​ ​(at​ ​least​ ​3​ ​mo),​ ​splenomegaly​ ​and​ ​no​ ​identifiable  cause​ ​of​ ​reactive​ ​neutrophilia​ ​including​ ​absence​ ​of​ ​a​ ​plasma​ ​cell​ ​neoplasm​ ​or,​ ​if​ ​present,​ ​demonstration​ ​of  clonality​ ​of​ ​myeloid​ ​cells​ ​by​ ​cytogenetic​ ​or​ ​molecular​ ​studies.      Differential​ ​Diagnosis:  Prior​ ​to​ ​reaching​ ​a​ ​diagnosis​ ​of​ ​CNL​ ​one​ ​must​ ​exclude​ ​processes​ ​capable​ ​of​ ​causing​ ​a​ ​reactive  neutrophilia​ ​or​ ​a​ ​leukemoid​ ​reaction.​ ​ ​Granulocytic​ ​dysplasia​ ​or​ ​evidence​ ​of​ ​monocytosis​ ​would​ ​suggest  an​ ​alternate​ ​diagnosis​ ​such​ ​as​ ​atypical​ ​CML​ ​(aCML)​ ​or​ ​chronic​ ​myelomonocytic​ ​leukemia​ ​(CMML).  Cytogenetic​ ​and​ ​molecular​ ​analysis​ ​were​ ​done​ ​and​ ​were​ ​negative​ ​ ​for​ ​BCR/ABL1​ ​excluding​ ​the​ ​diagnosis  of​ ​CML.​ ​Similarly,​ ​there​ ​was​ ​no​ ​evidence​ ​of​ ​other​ ​classic​ ​BCR/ABL1-negative​ ​MPNs​ ​such​ ​as​ ​polycythemia  vera​ ​(PV),​ ​essential​ ​thrombocythemia​ ​(ET)​ ​and​ ​primary​ ​myelofibrosis​ ​(PMF).​ ​ ​Further​ ​molecular​ ​testing  was​ ​completed​ ​and​ ​were​ ​negative​ ​for​ ​ ​rearrangements​ ​of​ ​JAKV617F,​ ​PDGFRA,​ ​PDGFRB,​ ​and​ ​FGRF1.  Peripheral​ ​blood​ ​smears​ ​revealed​ ​a​ ​leukocytosis​ ​(>25​ ​x10​9​/L.)​ ​with​ ​a​ ​ ​increased​ ​numbers​ ​of  mature-appearing​ ​neutrophils​ ​(>80%).​ ​The​ ​bone​ ​marrow​ ​was​ ​hypercellular​ ​at​ ​90​ ​%,with​ ​a​ ​increased​ ​M/E  ratio​ ​>10%,​ ​no​ ​increase​ ​in​ ​myeloblasts,​ ​ ​no​ ​dysplasia​ ​was​ ​noted​ ​and​ ​the​ ​pathologist​ ​referred​ ​to​ ​the  lymphoplasmacytic​ ​complement​ ​as​ ​being​ ​“unremarkable”.      9        References  1. Am.​ ​J.​ ​Hematol.​ ​91:342–349,​ ​2016.​ ​2015​ ​Wiley​ ​Periodicals,​ ​Inc  2. https://www.researchgate.net/publication/269718702_Molecular_genetics_of_chronic_neutrophi lic_leukemia_chronic_myelomonocytic_leukemia_and_atypical_chronic_myeloid_leukemia  [accessed​ ​Oct​ ​23,​ ​2017]  3. Maxson,​ ​Julia​ ​E.,​ ​and​ ​Jeffrey​ ​W.​ ​Tyner.​ ​"Genomics​ ​of​ ​chronic​ ​neutrophilic​ ​leukemia."​ ​Blood​ ​129.6  (2017):​ ​715-722.​ ​Web.​ ​23​ ​Oct.​ ​2017.​ ​http://www.bloodjournal.org/content/129/6/715.abstract  4. Uppal​ ​G,​ ​Gong​ ​J​ ​Chronic​ ​neutrophilic​ ​leukaemia.​ ​Journal​ ​of​ ​Clinical​ ​Pathology​ ​Published​ ​Online  First:​ ​16​ ​June​ ​2015.​ ​Doi:​ ​10.1136/jclinpath-2015-203060     Read​ ​more​ ​on​ ​our​ ​website  ​ ​Samantha​ ​Dewey,​ ​MLS(ASCP)SH  ©​ ​Hematology​ ​Interest​ ​Group   10