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

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