TRISOMY-6 AND DOUBLE MINUTE CHROMOSOMES IN A CASE OF CHRONIC MYELOMONOCYTIC LEUKEMIA

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-rela ted 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 associat ed with chemotherapy resistance and disease aggressiveness, in our cas e, the c-myc oncoprotein was not positively expressed. The patient rec eived chemotherapy and complete hematological remission rr as successf ully achieved. (C) Elsevier Science Inc., 1998.