Homogeneously Staining Regions or Double Minute Chromosomes in Leukemia

Homogeneously Staining Regions (HSRs) or Double Minute Chromosomes (DMs) are the cytogenetic hallmarks of genomic amplification in cancers and derive from the breakpoint region of translocation event. The relationship of DMs/HSRs and malignancies seems to be well established and indeed DMs/ HSRs have not, so far, been observed in non malignant cells. DMs/ HSRs were first described in a direct preparation of cells from a patient with untreated bronchogenic carcinoma (DMs originating from chromosome 19).