A 65-year-old woman with chronic myelomonocytic leukemia was shown to
have trisomy 6 and multiple double minute chromosomes. The patient had
no history of prior exposure to any mutagenic or carcinogenic agents. To
our knowledge, this is the first report for presence of only these two
aberrations. The expression of several oncoproteins and once-related
proteins was detected immunohistochemically in bone marrow cells. Among
them, only the bcl-2 oncoprotein was positively stained in 100% of
myeloblasts. Although the c-myc oncogene is frequently reported to be
overexpressed in myeloid disorders with double minutes and associated
with chemotherapy resistance and disease aggressiveness, in our case,
the c-myc oncoprotein was not positively expressed. The patient received
chemotherapy and complete hematological remission rr as successfully
achieved. (C) Elsevier Science Inc., 1998