A patient with M5b acute nonlymphoblastic leukemia (ANLL) and a 47,XXX
del(11) (q23) karyotype is described. Partial remission was obtained
after treatment with daunorubicin, arabinosylcytosine and VP-16. Subse
quently, two courses of chemotherapy for resistant ANLL were administe
red without achieving complete remission. Abnormalities of chromosome
11 are typical of M4 and M5 ANLL. X trisomy is one of the most common
human aneuploidia; however, correlation with increased incidence of he
matological neoplasia has not been described.