Chromosomes and causation of human cancer and leukemia. XXXII. Unusual features of Ph1-positive acute myeloblastic leukemia (AML), including a review of the literature

Abstract

Five cases of Ph¹‐positive AML were studied. In all cases a Ph¹‐chromosome was shown with banding techniques to be due to a translocation between chromosomes #9 and #22. Cases 1 and 4 were found to have more than one Ph¹ with evidence of only one Ph¹‐translocation accompanying other chromosome abnormalities. Two cases represented an unusual pattern of appearance and disappearance of the Ph¹‐positive clone during their clinical courses: Case #2 was originally Ph¹‐positive (46,XY,Ph¹) but two months before his expiration, the Ph¹‐positive clone was completely replaced by a newly developed Ph¹‐negative clone with an abnormal chromosome #21 (46,XY,21q+), whereas case #3, primarily Ph¹‐negative, developed a Ph¹‐positive clone among the previously karyotypically normal cells one month before death. The Ph¹‐positive AML cases presented have been discussed in relation to: 1) the genesis and significance of the Ph¹‐positive clone, 2) differentiation from the blastic phase of CML and 3) the general experience with Ph¹‐positive acute non‐lymphocytic leukemia (ANLL), the world literature of which have been tabulated.