Importance of molecular tests in myeloproliferative neoplasia with eosinophilia and PDGFRB rearrangement. Case Report

Importancia de las pruebas moleculares en neoplasia mieloproliferativa con eosinofilia y reordenamiento PDGFRB. Reporte de caso

Reactive eosinophilia occurs due to the overproduction of cytokines such as IL-3, IL-5 or GM-CSF, which are associated with allergies, infectious processes, medications, autoimmune disorders or rarely hematological neoplasms. Clonal eosinophilia is frequently associated with myeloid neoplasms such as: myeloproliferative neoplasms, chronic eosinophilic leukemia not otherwise specified, myeloproliferative/myelodysplastic neoplasms and, rarely, in acute myeloid leukemia or acute lymphoid leukemia/lymphoma (ALL/Lymphoma). In developing countries, the diagnosis of myeloproliferative neoplasms with eosinophilia is generally made by morphological data, flow cytometry, and molecular or genetic tests. Sometimes, the latter are not included due to the existence of barriers of access to the health system (costs, profitability or delays in administrative processes) and that diagnosing is delayed. This case report allows us to see the importance of using molecular tests as diagnostic criteria, because hematological neoplasms related to eosinophilia such as: chronic myeloid leukemia (CML), myelodysplastic/myeloproliferative syndrome of atypical chronic myeloid leukemia (MDS/MPN-AMLCa) or myeloid neoplasms with eosinophilia and rearrangements of some genes such as PDGFRA, PDGFRB, FGFR1 or PCM1-JAK2 could show similar morphological characteristics, their treatment is different and can have a great impact on the patient's health, since a delay in introduction of imatinib therapy, decreasing median survival to less than two years, producing heart damage or a possible transformation to an acute process.