EXTRAMEDULLARY BLASTIC TRANSFORMATION IN A CHILD WITH ADULT CHRONIC MYELOCYTIC-LEUKEMIA

We report a case of Philadelphia chromosome positive (Ph+) chronic myelocytic leukemia (CML) in a 4-year-old child presenting with a one-sided cervical chloroma (granulocytic sarcoma) of 5 months duration preceded by an inflammatory reaction in the same area. Blood and bone marrow were consistent with CML in chronic phase. Cytogenetic analysis of blood, bone marrow and chloroma showed, in addition to the classical Ph+ cell line, another clone with additional aberrations: 50,XY,+Y, +8,t(9;22)(q34;q11), +19,+21, present predominantly in the chloroma. In conclusion, this is the first report of a Ph + CML in a young child with a chloroma as an isolated extramedullary localization of blastic transformation. It is hypothesized that local events such as inflammation might be inductive of extramedullary blastic transformation.