Biphenotypic Acute Leukemia: Description of a Case and Literature Review

Introduction: "Ambiguous lineage acute leukemias" including biphenotypic acute leukemia are subtypes of acute leukemia (AL) generally representing less than 5% of all acute leukemias. We report a case of biphenotypic acute leukemia (T and B) diagnosed in the clinical hematology department of Dakar.

Observation: This was a 17-year-old female patient, with no specific pathological history, referred for exploration of a bicytopenia associated with hyperleukocytosis that appeared 2 months before. The clinical examination showed an alteration of general state of health (PS WHO 3), an anemic syndrome, a sepsis with a pulmonary focus and a tumor syndrome (nodes and splenomegaly). The blood count showed a hyperleukocytosis of 94.15 G/L, an anemia of 3.7 g/dl normochromic normocytic aregenerative and a thrombocytopenia of 14 G/L. The blood smear showed 34% of blasts cells. The myelogram study showed an acute lymphoblastic leukemia. Immunophenotyping revealed partly T-type blasts (CyCD3+; sCD3-; CD7+; heterogeneous CD2 and CD5), B cells (CD19+ and CD79a+) and absence of aberrant myeloid markers. Replacement therapy with blood products (red blood cells and platelets concentrates) was provided to the patient. The short-term evolution was marked by a worsening of the clinical presentation and a mortality at day 3 of hospitalization.

Conclusion: Bi-phenotypic acute leukemia is a very rare cytological entity with a poor prognosis. Systematization of flow cytometry in our countries with limited resources would help to better diagnose AL.