A complicated translocation involving five chromosomes (Nos. 9, 11, 12, 21 and 22) in a patient with chronic myelocytic leukemia (CML).

A new complicated Ph1 translocation involving five chromosomes, t(9;22;21;11;inv ins(12)-(q15p12p13))(q34;q11;q22;q13;q15), was found in a 64-year-old Korean woman with chronic myelocytic leukemia (CML). At presentation, the patient was found to be in the accelerated phase, she entered the chronic phase after six cycles of chemotherapy including a vincristine (VCR) and prednisolone (PSL) regimen (VP). The chronic phase continued for 2 years, and 33 months after her first admission she died due to severe pneumonia and congestive heart failure in the re-accelerated phase. In the literature, the frequency of the involvement of chromosome No. 11 in three-way Ph1 translocations (4.9%) is lower than that in four- and five-way Ph1 translocations (33.3%). It may be worth noting that chromosome No. 11 is easily involved in highly complicated Ph1 translocations.