Chronische leukemie of leukemoïde reactie? Het belang van vroegtijdige lymfeklierdiagnostiek

Ninety-five percent of paediatric haematologic malignancies concern acute leucaemias and lymphomas. Only 2 to 5% are chronic myeloproliferative disorders, mostly chronic myeloid leucaemias (adult or juvenile) and myelodysplasias. On the basis of two case reports of children with signs of myeloproliferation we illustrate the need for early examination of extramedullary sites, e.g. lymph nodes, to differentiate between myeloproliferative disorders and reactive bone marrow hyperplasia, so-called leucaemoid reaction. Leucaemoid reactions are seen mostly in association with severe infections and solid tumors, particularly in case of bone marrow invasion. We were able to diagnose T-cell lymphoma at an early stage in our patients after the investigation of lymphnodes by immunologic, cytogenetic and Southern blot techniques. Both cases show the importance of early investigation of extramedullary localisations in children with suspected haematologic malignancy; at least in those patients in whom examination of bone marrow and blood does not confirm acute leucaemia.