<prompt> In a patient with acute leukemia, immunophenotype pattern is CD 19ve, CD 10ve, CD33ve, CD13ve. He may probably have-Biphenotypic leukemiaALLAML-M2AML-Mo  <response>: Answer is A Biphenotypic leukemia Biphenotypic leukemias are leukemias that express features of more than one lineage. The patient in question has a rare leukemia that expresses both, myeloid antigens CD 33 and CD 13 and Lymphoid antigens of B cell lineage CD 10 and CD 19 and hence can be described as a Biphenotypic leukemia. Biphenotypic Leukemias Biphenotypic Leukemias are rare acute leukemias that express both myeloid and lymphoid associated antigens to a degree that no single lineage can be assigned. Scoring systems have been proposed to more precisely defines biphenotypic leukemias and to distinguish these cases from ALL with myeloid antigen expression or AML with lymphoid antigen expression Scoring System for Biphenotypic Acute Leukemia Points B Lineage T Lineage Myeloid Lineage 2 CD79a CD3 mcyt Anti-MPO monoclonal Cyt IgM Anti-TCR aB MPO cytochemistry Cyt CD22 Anti-TCR yS I CDI9 CD2 CDII7 CD10 CD5 CD 13 CD20 CD8 CD33 CDIO CD65s Anti-MPO polyclonal 0.5 TdT TdT CD I4 CD24 CD7 CD 15 CD 1 CD64 M, membrane; cyt, cytoplasm; MPO, myeloperoxidase A diagnosis of biphenotypic acute leukemia requires a score of more than 2 points for the myeloid and one of the lymphoid lineages. The patient in question scores two points for myeloid lineage and two points for lymphoid B cell lineage and hence can be classified as a Biphenotypic Leukemia 