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

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.