Acute leukemia of mixed phenotype: presentation of a pediatric case from Peru

Vera S.T.; Vale A.O.M.C.E.; Vásquez W.C.C. · Revista Cubana de Hematologia, Inmunologia y Hemoterapia (2022)

Resumen

Introduction: Acute leukemias of ambiguous lineage represent a heterogeneous group of leukemias without a clear differentiation of the cell lineage. They constitute about 2 to 5 % of all acute leukemias. Objective: To describe a case of acute leukemia of mixed phenotype (LAFM) in a 4-year-old pediatric patient from Lambayeque, Peru. Case presentation: A peripheral blood sample from a 4-year-old boy was evaluated, whose immunophenotype by flow cytometry showed a population, corresponding to 94 % of total cellularity, of myeloid lineages compatible with differentiation to neutrophil lineage and in less to monocytic/dendritic cell (CD123 high), with expression of myeloperoxidase (MPO) and CD33 high; CD13, CD64 and CD66c partial; and expression of B lymphoid lineage markers (CD19 and CD22 high). This phenotype requires ruling out the t (8; 21), and abnormalities of the MLL gene. Due to the aforementioned findings, the present leukemia was classified as acute leukemia of mixed phenotype, B/Myeloid. Conclusions: It was concluded as an acute leukemia of mixed phenotype B/Myeloid, with the peculiar inclination of the myeloid lineage towards neutrophils and to a lesser extent towards monocytic/dendritic cell.