An adult case of acute biphenotypic leukemia with characteristic mixed morphology.

A case of acute biphenotypic leukemia with mixed blast morphology and combined myeloid and T-lymphoid features is reported. The leukemic cells consisted of small lymphoid hand-mirror blasts and large blasts with cytoplasmic granules and rare Auer rods. The cells expressed myeloid and immature T-lymphoid features by cytochemistry and immunophenotyping, however T cell receptor genes were in germline configuration.