A Case of Mixed Lineage Acute Non-lymphocytic Leukemia with t(5;12)(p13;p13)

: A two-year-old boy had mixed lineage acute non-lymphocytic leukemia (ANLL) with a 46,XY, t(5;12)(p13;p13) karyotype. He was admitted to the hospital with fever and petechiae. Morphological and cytochemical characteristics showed the blasts to meet the standard French-American-British criteria for M1, but surface marker analysis showed the blasts to express both myeloid (CD33: 91.3%) and T-cell (CD2: 82.3%, CD7: 97.9%) antigens. The boy was treated with an ANLL protocol, and successfully brought to a remission which has continued for more than 30 months.