Karyotypic evolution in a granulocytic sarcoma developing in a myeloproliferative disorder with a novel (3;4) translocation.

A 59-year-old man presented with a granulocytic sarcoma arising in the manubrium, and splenomegaly. The blood count showed 1.2 x 10(9)/l eosinophils and a marrow aspirate was hypercellular with eosinophilia. Cytogenetic analysis of the marrow revealed a novel t(3;4) (p13;q12) and analysis of cells aspirated from the granulocytic sarcoma showed the same abnormality and an additional trisomy 8. Intensive chemotherapy and local radiotherapy led to resolution of the chest mass but persistence of the chromosome translocation in the marrow.