Adult-type CML in childhood: case report and review.
The clinical, hematologic, and cytogenetic features of ACML in children appear to be identical to Ph1-positive CML seen in adults. From our review of the literature, one could anticipate that a child with this condition would have a response to therapy and an anticipated survival similar to that seen in adults. This situation is quite different when one compares adults with ALL to children with the same disease. It has been suggested that Ph1-positive CML is an acquired, postzygotic abnormality induced by environmental agents. It is difficult to reconcile this hypothesis with the fact that this condition can be seen in infants as young as 5 months of age and the general belief that environmental carcinogens take many years to produce malignant changes in cells. Ph1-positive CML has been associated with atomic bomb exposure and it is of interest to note that two patients in the present series had received radiation. For both children and adults, bone marrow transplantation during the chronic phase is the most successful therapy if a suitable donor is available. Recently, successful marrow transplantation during the accelerated phase has also been reported. For patients without a suitable donor, control of the disease with either busulfan or hydroxyurea and attempts to induce a remission with chemotherapy during the accelerated or blast phase is the best current alternative. For patients whose blasts have lymphoid characteristics such as TdT activity, vincristine and prednisone may be successful. For those patients with a myeloid or mixed lymphoid-myeloid transformation, no chemotherapy regimen has been successful. An aggressive approach such as that described by Weinstein et al. for the treatment of acute nonlymphocytic leukemia might prove beneficial.