Unusual and unrelated polyclonality in a case of myeloid disease

A case of myelofibrosis with myeloid metaplasia was found to have five cytogenetically unrelated clones in the marrow, four of these clones being abnormal. We present the hypothesis that the hematologic disease in this patient was caused by a genetic event not discernible microscopically (cytogenetically) and that the distinctive abnormal clones may have been generated at different anatomic sites.