Myeloid neoplasm with eosinophilia and rearrangement of platelet-derived growth factor receptor beta gene in children: Two case reports

BACKGROUND: Myeloid neoplasm (MN) with eosinophilia and rearrangement of platelet-derived growth factor receptor beta (PDGFRB) shows a good therapeutic response to imatinib in adults. MN is rarely found in children, and the efficacy of imatinib on pediatric patients remain unclear. CASE SUMMARY: We report 2 pediatric cases diagnosed with MN with eosinophilia and PDGFRB rearrangement who were treated with imatinib. Case 1 was a 1-year-old girl admitted to the hospital because of “abdominal distension with hyperleukocytosis for 3 mo”. She had leukocytosis, anemia, and eosinophilia (the absolute eosinophil count (AEC) was 8960/μL), and her fluorescence in situ hybridization (FISH) test revealed that PDGFRB rearrangement was detected in 70% of 500 interphase cells. Case 2 was a 2-year-old girl admitted to the hospital because of “recurrent fever and rashes for 1 mo”. Her blood cell count showed an AEC of 3540/μL. The FISH test revealed that PDGFRB rearrangement was detected in 71% of 500 interphase cells. Both patients were diagnosed as MN with eosinophilia and PDGFRB rearrangement. Imatinib was added into their treatment regimen. As expected, complete hematologic remission was achieved after 1 mo of treatment, and symptoms disappeared. CONCLUSION: Although MN with eosinophilia and PDGFRB rearrangement usually occurs in adults, it can be found in children. The therapeutic benefits of imatinib in these 2 pediatric patients were consistent with its reported effects in adult patients.