Isolated myelosarcoma in children--update and review.

Primary myelosarcomas, also called leukemia cutis, granulocytic sarcomas or chloromas, are rare extramedullary manifestations of acute myeloid leukemia (AML) which precede bone marrow involvement. Skin infiltration was the most frequent localization associated with a myelomonocytic differentiation. Although first remission was achieved by most children, risk of relapse seemed to be increased. This might be caused by the specific biology of myelosarcomas, but also may be the result of delayed or reduced treatment. During the AML-BFM-studies 87/93/98 (11/1987-7/2000) 37 children with isolated myelosarcomas were diagnosed. Eighteen of the 37 patients survived with a 5-year overall survival estimation of 0.54+/-0.09 compared to 0.59+/-0.02; p(log rank) = 0.94. However, reduced or delayed treatment in 17 children led to an increased relapse rate of 71% compared to 35% in children treated soon after diagnosis. The 5-year overall survival in these patients was 0.41+/-0.11. According to our experience and review of the literature, an early diagnostic workup is needed in children with unusual skin lesions or tumors, considering myelosarcoma as primary manifestation of AML. Intensive AML-specific chemotherapy is generally recommended soon after diagnosis.