A Rare Presentation of ph Chromosome: idic der (22q11) in Blast Crisis Chronic Myeloid Leukemia

Abstract

The ider(22)t(9;22)(q34;q11) is a rare secondary karyotypic abnormality of Ph chromosome positive chronic myeloid leukemia associated with disease progression, poor clinical outcome and short survival in most of the previously reported cases. The present case of CML with idic der(22)t(9;22)(q34;q11) or idic der Ph with hybrid transcript ratio of BCR-ABL being 97% showed a complex karyotype: 48,XY,+8,t(9;22)(q34;q11)i dic(22)(q11),+idic der(22)t(9;22)(q34;q11). On treatment with Imatinib the initial transcript ratio was reduced to 12.125%, 0.932% but later increased to 93%. The patient developed extra medullary myeloid cell tumor of testis after a year of treatment followed by the detection of T3151 mutation. Cytogenetics provides an evidence for progression of disease at an earlier phase than other markers in this case.