Evaluation of children with myelodysplastic syndrome: Importance of extramedullary disease as a presenting symptom

Thirty-three children diagnosed with primary myelodysplastic syndrome (MDS) in a single institution over an 8 year period were evaluated with special emphasis on children who presented with extramedullary disease (EMD). EMD w as present at diagnosis in 12 (36%) of the 33 children with MDS. Three pati ents with juvenile myelomonocytic leukemia (JMML) and 2 patients with chron ic myelomonocytic leukemia (CMML) presented with pleural effusion, Pericard ial effusion was present in 3 of these patients, two of whom also had throm bosis, Pyoderma gangrenosum, relapsing polychondritis were the initial find ings in another two cases with JMML. Lymphadenopathy (n=1), gingival hypert rophy (n=2), orbital granulocytic sarcoma (n=1) and spinal mass (n=1) were the presenting findings in 5 patients with refractory anemia with excess of blasts in transformation. Since high-dose methylprednisolone (HDMP. 20-30 mg/kg/day) has been shown to induce differentiation and apoptosis of myeloi d leukemic cells in children with different morphological subtypes of acute myeloid leukemia in vivo and in vitro, 25 children with de novo MDS were t reated with combined HDMP and cytotoxic chemotherapy. Dramatic improvement of EMD and decrease in blast cells both in the peripheral blood and bone ma rrow were obtained following administration of short-course HDMP treatment alone as observed in children with AML. HDMP, combined with low-dose cytosi ne arabinoside and mitoxantrone were used for the remission induction. Remi ssion was achieved in 8 (80%) of 10 children who presented with EMD and in 9 (60%) of 15 children without EMD. Long-term remission (>6 years) was obta ined in 4 (two with JMML and two with CMML), three of whom presented with E MD. In conclusion EMD can be a presenting finding in childhood MDS as observed in adults. In addition, the beneficial effect of HDMP combined with more in tensive chemotherapy should be explored as alternative therapy in children with MDS not suitable for bone marrow transplantation.