Oil Red O positive vacuolated blasts in a case of CD45 negative, CD19 negative B-lymphoblastic leukemia

Abstract B- lymphoblasticleukemia is a clonal hematopoietic disorder of precursors B- lymphoblastsbeing most frequently encountered in children. Expression of CD19, a pan B-cell marker is noted in the majority of the cases with lack of CD19expression being extremely rarely reported in the medical literature. We report the very rare case of a B- lymphoblasticleukemia with a triple negative immunophenotype: CD19 negative, CD45 negativeand CD10 negativewith vacuolated lymphoblastsand an aleukemic presentation in a 20-year-old man.