[Biphenotypic acute leukaemia with Burkitt-like cytology]. / Leucémie aiguë biphénotypique avec aspect cytologique de type Burkitt.

Biphenotypic acute leukaemia (BAL) represents about 5% of adult acute leukaemia. Based on a previously described scoring system, the European Group for Immunologic Classification of Leukaemia (EGIL) proposed a set of diagnostic criteria for BAL. This scoring system is based on the number and degree of the specificity of several markers for myeloid or T/B lymphoid blasts. Here, we report the case of a BAL with Burkitt-like cytology, corresponding to "the acute lymphoblastic leukaemia, Burkitt type" L3 for the FAB classification. By flow cytometry, the blasts showed a positivity for B lymphoid cytoplasmic (CD79a and mu) and membrane (CD19, CD22, CD24, IgM) markers AND a positivity for the myeloid (CD13, CD33, CD65, CD15) markers.