A Rare Case of Pediatric Chronic Myelogenous Leukemia Presenting With Severe Thrombocytosis Without Leukocytosis

Abstract

Pediatric chronic myelogenous leukemia is uncommon. We report a pediatric patient with chronic myelogenous leukemia presenting with a normal white blood cell count and no circulating immature myeloid cells. The patient presented with extreme thrombocytosis (platelet count range: 2175-3064 Â 10 9 /L) noted incidentally. No splenomegaly was found. Examination of the bone marrow aspirate revealed normal cellularity and normal myeloid: erythroid ratio with marked megakaryocytic hyperplasia. Molecular studies on the bone marrow aspirate detected both the major BCR/ABL1 p210 fusion transcript (9280 copies; p210/ABL1 ratio: 38.2%) and the minor p190 transcript (below limit of quantitation). The platelet count normalized within 2 weeks after treatment with the second-generation tyrosine kinase inhibitor dasatinib. Follow-up after 3 months revealed a 1.87 log reduction in p210 transcripts compared to diagnosis and no detectable p190 transcripts. This case highlights the need to include BCR/ABL1 fusion testing to accurately diagnose pediatric patients presenting with isolated thrombocytosis.

Chronic myeloid leukemia in childhood: a case report

“…Pediatric CML patients typically have higher mean WBC counts, more pronounced splenomegaly, and pursue a more aggressive clinical course when compared to adult CML patients. 3 Here, we report a case of CML in a three-year patient because of its uncommon incidence in childhood.…”

Pediatric Chronic Myeloid Leukemia Presenting With Extreme Thrombocytosis and Acute Upper Gastrointestinal Hemorrhage: A Case Report

“…6 Including the case mentioned above, only 6 children with CML presenting with isolated extreme thrombocytosis have been reported (Table 1). [7][8][9][10][11]…”

“…Including the case mentioned above, only 6 children with CML presenting with isolated extreme thrombocytosis have been reported (Table 1). 7–11 These cases emphasize the need to detect BCR-ABL transcripts and the Philadelphia chromosome when patients present with thrombocytosis, without an elevated WBC count and splenomegaly, or with atypical BM results.…”

BCR/ABL-1-Positive Myeloproliferative Neoplasm Presenting with Isolated Remarkable Thrombocytosis with Atypical Clinicopathological Features: Discussion from Management Point of View

“…Recently, a number of reports have described the coexistence of the JAK2V617F mutation in patients with CML, BCR-ABL1+. In some cases, the mutated JAK2 was detected after treatment of CML with TKI [18,19] but retrospective analyses of the initial specimen in those cases demonstrated that the mutated JAK2 was present at the time of the initial diagnosis of CML. In our case JAK-2 was performed initially at diagnosis and retested after treatment of CML and found to be negative.…”