Acute Leukemias with Simultaneous Expression of B- and T-Lymphoid Markers-A Comprehensive Diagnostic Approach for Immunophenotypic characterization.

Acute leukemias often show simultaneous expression of multiple lineage antigens and pose diagnostic challenges to classify them. Strict adherence to WHO criteria is essential to classify leukemias as mixed phenotype acute leukemia or leukemias of a specific lineage with aberrant expression of cross lineage antigen. Here, we present three cases of acute leukemias with co-expression of B- and T-lymphoid markers and a comprehensive use of flowcytometric immunophenotyping and immunohistochemistry to reach a correct diagnosis. However, clinically, all 3 cases presented similarly, with lymphadenopathy. We attempt to highlight the overlapping clinical presentation and immunophenotypic profile, and emphasize the need for careful use of multiple modalities before rendering a diagnosis.