Chronic Myeloid Leukemia Harboring a Novel Four-Way Variant Translocation t(7;22;9;15)(p15;q11.2;q34.1;q22) With Cryptic Double Philadelphia Chromosomes.

Variant Philadelphia chromosomes are occasionally observed in chronic myeloid leukemia. Among them, four-way variant Philadelphia translocations are particularly rare. Double Philadelphia chromosomes, representing an additional Philadelphia chromosome, are also uncommon and have been reported to be associated with disease progression and therapeutic challenges. We report a case of chronic myeloid leukemia with a novel four-way variant translocation t(7;22;9;15)(p15;q11.2;q34.1;q22) accompanied by cryptic double Philadelphia chromosomes. Despite these unfavorable cytogenetic features, the patient was successfully treated with dasatinib and achieved a complete hematologic response.