JAK2-positive acute myeloid leukemia de novo or secondary transformed from myeloproliferative neoplasm? Case report

Abstract

Introduction and Aim. JAK2 V617F mutation is typically found in Ph-negative myeloproliferative neoplasms. This molecular abnormality very rarely occurs in de novo acute myeloid leukemia (AML). Data on the effective treatment of AML with JAK 2 mutation are limited. Our case report presents the results of successful patient’s management with JAK2-positive AML, treated by azacitidine and ruxolitinib combination. Case Report A 65-year-old man presented to the hematology department in October 2021 with complains of discomfort in the right half of the body, the presence of a dense formation (intermuscular hemorrhage) on the back on the right, general weakness, shortness of breath, fatigue. From anamnesis it is known that symptoms developed rapidly during the previous week. Anamnesis vitae: in 2012 patient underwent complex treatment of Ca pulm. sinistra T2aN0M0, gr. IB, clinical group ІІ. Physical examination revealed large intermuscular hematoma of the back on the right, blood imbibition of soft tissues from the neck to the lower back. The computed tomography showed massive hemorrhagic infiltration of the trunk muscles on the right, infiltration of the upper mediastinum, mediastinum shifted to the left (after operative treatment in 2012), splenomegaly 74×125×155 mm. In hemogram: erythrocytes (RBC) 5.1×1012/L, hemoglobin (HGB) 89 g/L, platelets (PLT) 999×109/L, leukocytes (WBC) 32.2×109/L, blast cells 5%, monocytes 39%. In myelogram: bone marrow hypercellular, polymorphic, infiltrated with blast cells 36.8%, some of which contained Auer's rods; the erythron was hyperplastic, without rejuvenation, with signs of dyserythropoiesis; the granulocytic line narrowed, with a predominance of mature forms of granulocytes; the megakaryocytic line with reactive changes. Bone marrow flow cytometry revealed signs of pronounced clonal proliferation of blast cells of myeloid origin (makes up to 34% of all nuclear cells in the sample): 1st clone up to 18%, with phenotype: CD34+19- 117+38(dim)+10-36-14-HLA-DR-; 2nd clone up to 16%, with the phenotype: CD34- 19-117-38+10-36+14+HLA-DR(dim)+/-11c+11b+3-4+/-56-. Molecular-genetic tests: FISH BCR/ABL1; FLT3 ITD; Inv(16)(p13q22) were not detected. Karyotyping: cytogenetically normal male karyotype was revealed 46,XY [20]. These changes corresponded with AML (М4).