Hypereosinophilia in childhood acute lymphoblastic leukaemia at diagnosis: report of 2 cases and review of the literature

Abstract

Hypereosinophilia as first clinical presentation has rarely been reported in paediatric acute lymphoblastic leukaemia. It is commonly associated with specific cytogenetic abnormalities. Although eosinophilia is considered a reactive, non-neoplastic epiphenomenon, it adversely affects patient outcomes, both in children and adults. We describe herewith two paediatric patients who had marked eosinophilia at onset of acute lymphoblastic leukaemia. We point out the importance of a correct differential diagnosis in persistent, unexplained peripheral hypereosinophilia. Clinicians should keep in mind that eosinophilia can be part of the overall pattern of acute leukaemia and therefore needs to be properly investigated. We also provide some recommendations for an appropriate approach to hypereosinophilia - related morbidities.

Figure 1

Patients’ hematopathology and radiology. a) Peripheral smear showing lymphoblasts and eosinophils (May-Grünwald -Giemsa); b) Bone marrow smear showing FAB L1-lymphoblasts, eosinophils and neutrophils (May-Grünwald - Giemsa); c) Skin biopsy showing perivascular infiltration of small lymphocytes and eosinophils (Hematoxylin-eosin, original magnification × 100); Inset: lymphocyte’s nuclear TdT positivity in immunohistochemistry (ABC staining, × 400); d) CT scan demonstrating tibial osteolytic area with interruption of cortical bone profile.