Double-minute chromosomes in the leukocytes of a patient with a previous history of cervical carcinoma.

Double-minute chromosomes (DMs) were observed in repeated samples in the leukocytes of a patient with a previous history of cervical carcinoma. The most interesting cytogenetic finding was the coexistence of DMs and a dicentric chromosome along with chromosome- and chromatid-type breaks and gaps. This observation suggests that DMs might originate through the breakage of existing chromosomes. The presence of DMs in leukocytes may also indicate the possibility that certain common agents cause DMs in tumor cells as well as in normal cells.