The Principles of Clinical Cytogenetics - Extra Materials - Springer

Cytogenetics of Hematologic Neoplasms 373
Table 2
Major Routes of Cytogenetic Evolution in CML Blast Crisis
Additional change Frequency (%)
+Pha 15
i(17q) 12
+8 11
+Ph, +8 8
+8,i(17q) 7
+Ph,+8,+19 5
+Ph,+19 4
+8,+19 2
+Ph,+8,i(17q) 2
+19 1
i(17q),+Ph 1
+8,i(17q),+19 1
+Ph,+8,i(17q), +19 1
i(17q),+19 >1
i(17q),+19, +Ph >1
a +der(22)t(9;22)(q34.1;q11.2).
when used in the early course of the disease. In conclusion, cytogenetic and molecular evaluation of
any cases of suspected CML are critical in the diagnosis and classification of this neoplasm.
Chronic Neutrophilic Leukemia
Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative disease characterized by
hepatosplenomegaly and sustained peripheral blood neutrophilia with bone marrow hypercellularity
as a result of a neutrophilic granular site proliferation. The lack of a Philadelphia rearrangement is
used as a diagnostic criterion for CNL. Whenever any evidence of a BCR/ABL1 translocation is seen,
even in chimeric or cryptic form, the diagnosis of CNL should not be made and the case should be
considered to be CML.
Cytogenetic changes in CNL are rarely seen and only about 10% of patients show nonspecific
chromosome abnormalities. The most commonly seen abnormalities are trisomy of chromosome 8
and 9 and deletion of chromosome 22q and 11q, and, as indicated previously, a Philadelphia rearrangement
is not present in any form (23–27).
Chronic Eosinophilic Leukemia
Chronic eosinophilic leukemia (CEL) is characterized by trisomy of chromosome 8 and a translocation
between chromosomes 5 and 12 at bands q33 and p13, respectively [t(5;12)(q33;q13)], involving
the TEL and PDGFRβ genes (28–30). In addition, a dicentric (1;7) translocation, along with
aberrations involving 8p11 at the FGFR1 locus have been reported (28–30).
Other Chronic Myeloproliferative Diseases
Cytogenetic abnormalities commonly seen in polycythemia vera (PV) are an extra copy of chromosome
8 and/or 9 and deletions of 13q, 20q (see Fig. 2z,aa,w,x) and 1p11. Almost all cases transforming
into myelodysplastic syndrome show cytogenetic abnormalities, including the ones seen in
therapy-related MDS and AML (discussed later) (31–33).
In chronic idiopathic myelofibrosis (CIMF), an extra copy of chromosome 8, deletion of chromosome
20, and loss or deletion of chromosomes 7, 11q, and 13q have been seen in about 35% of cases
(34,35). In essential thrombocythemia (ET), trisomies of chromosomes 8 and 9, deletions of 13q