A case of acute myelomonocytic leukaemia with Philadelphia and small F group chromosomes

Inversion of chromosome 16 with the Philadelphia chromosome in acute myelomonocytic leukemia with eosinophilia. Report of two cases

Two cases are described with the rare combination of inv(16)(p13q22), strongly associated with acute myelomonocytic leukemia with eosinophilia, M4Eo, and the Philadelphia translocation, t(9;22)(q34;q11), hallmark of chronic myeloid leukemia (CML) and rarely found, (less than 1%), in acute nonlymphocytic leukemia. The patients were: case 1, a 9-year-old girl presenting with a white blood cell count (WBC) 42 x 10(9)/L with 32% blasts and bone marrow with blasts and eosinophil precursors consistent with M4Eo, and case 2, a 25-year-old man with WBC 34.7 x 10(9)/L with 13% blasts and bone marrow with features of M4Eo and basophilia. Both patients achieved remission but died following bone marrow transplantation in first remission (case 1) or in relapse (case 2). Cytogenetic findings were: case 1, at diagnosis, 46,XX,inv(16)(p13q22)(21)/46,XX,t(9;22) (q34;q11),inv(16)(8)/46,XX(10), and case 2, at diagnosis, 46,XY,t(9;22) (q34;q11),inv(16)(p13q22) (16) and in remission, 46,XY,t(9;22)(q34;q11) (1)/46,XY (24). Investigation of the breakpoint on 22 in case 1 with Southern blotting and the polymerase chain reaction demonstrated the presence of a p190 mRNA and a breakpoint typical of acute leukemia. Thus a diagnosis of M4Eo was supported by clinical and cytogenetic sequelae in each case; the Ph in case 1 was apparently secondary to inv(16), in case 2 the Ph probably preceded inv(16) in the etiology of the leukemia.

Trisomy 22--a new abnormality found in acute leukemia characterized by eosinophilia and monocytoid blasts expressing immature differentiation antigens

Bone marrow cells from three patients with acute myeloid leukemia, with marrow eosinophilia and monocytoid blasts, showed a new nonrandom chromosomal abnormality, trisomy 22. In two patients the classification of leukemia was M4 and in the third patient M2 (FAB classification). Pretreatment bone marrows in these patients revealed 31%, 30%, and 4% eosinophils, respectively. Blast cells isolated from peripheral blood were Ia-positive and expressed immature monocyte lineage antigens (U26, U28, U48) in 26%-92% of cells. All three patients had a population of bone marrow cells characterized by an extra chromosome #22. One patient also had inversion of chromosome #16. Trisomy 22, bone marrow eosinophilia, and monocytoid blasts displaying early monocyte differentiation antigens may represent a new subgroup of patients with acute myeloid leukemia.

Hematologic manifestations associated with deletions of the long arm of chromosome 20

We investigated 20 patients with hematologic disorders who had a clone of cells with a deletion of most of a chromosome #20 long arm (20q-) in the bone marrow. Three patients had polycythemia vera (PV), 6 had acute nonlymphocytic leukemia (ANLL), 8 had preleukemia (PL), and 3 had other myeloproliferative disorders. In our laboratory, a 20q- chromosome is found in 6% of patients with PV, 3% of patients with ANLL, and 1% of patients with PL. Among the 6 patients with ANLL and a 20q- abnormality, 3 had erythroleukemia. There were no apparent clinical differences among our patients with 20q- chromosomes compared with other patients with similar disorders who did not have a 20q- chromosome. The breakpoint of the 20q- anomaly, in each instance, was in band 20q11, but it occurred near the centromere at 20q1101 in 16 patients and at the distal part of this band at 20q1109 in 4 patients. Three of the 4 patients with a breakpoint at 20q1109 had PL.

Cytogenetic study in acute myeloid leukaemia using peripheral blood samples sent by post

The patterns of chromosomal abnormalities in acute myeloid leukaemia (AML) revealed by study of peripheral blood specimens (group A) up to seven days old were comparable to the results from fresh bone marrow (group B). However, a decreasing proportion of cases providing enough metaphases for study, an increasing proportion of cases with chromosomal abnormalities, a decreasing ratio AN:AN + AA (see footnote Table 1) and a decreasing percentage of chromosomally normal cells in AN cases were found with ageing of specimens, which clearly demonstrates that cells with a normal karyotype were more likely to lose the capacity for dividing and die off than abnormal ones during ageing of specimens. Since the cells in older specimens were less active in division, a prolonged culture time was used. The different times for the cells from older specimens to re-enter active proliferation in culture conditions appeared to have some cytobiological significance. Three cases with t(8q-; 21q+) were present in group A but none in group B. Two cases of APL both showed a t(15q+; 17q-) and the breakpoints seemed to be at 15q24 and 17q22. One case showed trisomy 8 and double minute chromosomes. The remission rate in AN patients was lower than in AA or NN patients.