[Report of a case of hybrid acute leukemia with t (12; 22) and literature review]

Abstract

Objective: To report a hybrid acute leukemia (HAL) patient with t (12; 22) (p13; q12).

Methods: Chromosome specimens were prepared by direct method and/or short-time culture of bone marrow cells. Karyotyping was performed by R-banding technique. Leukemia surface markers were detected by anti-biotin-biotin complex and monoclonal antibodies. Chromosome painting (fluorescence in situ hybridization, FISH) was performed by using whole chromosome 12 and 22 probes labeled with green and red fluorescence, respectively.

Results: The clinical and hematological findings were compatible with the diagnosis of HAL. Lymphoid and myeloid markers were positive on the leukemia cells. Karyotype analysis showed that the patient had t (12; 22) (p13; q12) translocation. A reciprocal translocation between chromosomes 12p and 22q was proved by FISH.

Conclusions: t (12; 22) translocation is a rare chromosome abnormality in leukemia. Patients with t (12; 22) had unique clinical, cytogenetic features. This translocation as a cytogenetic marker for poor-prognosis in leukemia needs to be further studied.