We described a primary AML-M4 case with cytogenetic rearrangements involving seven different chromosomes. According to the literature, not a single case of AML showed a der(4)t(4;7)(p13;q11.23), a der(11)(11qter->11p11.2::11p11.2->11q23::2p23->2pter), a der(17)t(4;17)(p13;p13), or a der(11)(11pter->11q13::22q11.2->22q13.3::11q13->11q21::7p12->7pter) . However, a t(2;11)(p23;q23) was observed in one case of refractory anemia with excess blasts-1 . To the best of our knowledge, the present case is the only one ever seen case of AML with these cytogenetic aberrations .
The common chromosomal abnormalities in the AML-M4 include monosomy 5 or del(5q), monosomy 7 or del(7q), trisomy 8, t(6;9) (p23;q34), and rearrangements involving the MLL gene mapped at 11q23 [del(11)(q23); t(9;11)(p22;q23), t(11;19)(q23;p13)], and Core Binding Factor B (CBFβ) mapped at 16q22 [del(16)(q22), inv(16)(p13q22), t(16;16)(p13;q22)] . However, in the present case both MLL genes were intact.
In general, a complex karyotype in MDS or AML is associated with a median survival of less than 1 year [11, 14]. Furthermore, the adverse prognostic effect of monosomal karyotype was evident both in the presence and absence of monosomy 5 and/or 7, which suggests that tumor suppressor or other critical genes are not necessarily clustered in specific chromosomes but are instead distributed across several chromosomes .
Monosomy 7 is a valuable prognostic marker in AML, and chromosome 7 defects are prominent cytogenetic lesions in primary myelofibrosis, associated with unfavorable prognosis; they present with high incidences after leukemic transformation . Similarly, deletions on 7p12 of IKZF1 gene (which encodes the transcription factor Ikaros) are associated with a very poor outcome and high relapse rate in B-cell acute lymphocytic leukemia . Monosomy 7 is known as a recurrent cytogenetic aberration in approximately 10% of adult and 5% of childhood AML cases . Jäger et al.  found two of seven myeloproliferative neoplasms patients with loss of IKZF1 had monosomy 7. This result suggests that IKZF1 may represent an important tumor-suppressor gene affected by monosomy 7 .
The International Prognostic Scoring System (IPSS) classifies cytogenetic and molecular genetic data in AML with clinical data into four risk groups: favorable, intermediate-I, intermediate-II and adverse . The adverse prognostic groups included inv(3)(q21q26.2) or t(3;3)(q21;q26.2); RPN1-EVI1; t(6;9)(p23;q34); DEK-NUP214; t(v;11)(v;q23); MLL rearranged; -5 or del(5q); -7; abnl(17p); complex karyotype .
Complex karyotypes, which occur in 10-12% of AML patients, have consistently been associated with a very poor outcome . A complex karyotype has been defined as the presence of 3 or more (in some studies ≥ 5) chromosome abnormalities. For AML it turned out that the presence of t(8;21), inv(16) or t(16;16), and t(15;17) ameliorates the adverse effect of increase karyotypic complexity . As indicated in the new WHO classification, cases with other recurring genetic abnormalities, such as t(9;11) or t(v;11), inv(3) or t(3;3), and t(6;9) should also be excluded from complex rearranged karyotype patient group , because these groups constitute separate entities. One striking observation is the increasing incidence of adverse versus favorable cytogenetic abnormalities with increasing age. This, at least in part, contributes to the poorer outcome of AML in older adults .
In conclusion, we reported a de novo case of AML-M4 with yet unreported translocation events involving seven different chromosomes. Taken together all findings an adverse prognosis for this specific AML-case must be considered.