[Immunophenotyping analysis of acute undifferentiated leukemia].

The diagnosis of acute undifferentiated leukemia (AUL) is made when the leukemic cells do not have cytologic or cytochemical features of myeloid cells, and do not express myeloid antigens (CD13, CD14, CD33, CD41 etc.) or lymphoid antigens (CD2, CD3, CD19, CD20, Sm Ig etc.). Most of these cells are reported to be positive for CD7, CD34, TdT and HLA-DR, either alone or in combination. Cell lineage can be suspected in most AUL cells by genotypic analysis, phenotypic analysis after culturing with TPA, or peroxidase activity by ultrastructural or immunohistochemical analysis, which indicates the heterogeneity of AUL. The patients with AUL appear to have a poor prognosis with conventional chemotherapy.