Lymphoblastic leukemia with surface light chain restriction: A diagnostic dilemma.

Surface light chain expression is a feature of mature B‑cell neoplasms. Light chain restriction in precursor B acute lymphoblastic leukemia is infrequently seen. We report a case of a 28‑year‑old female with non‑FAB L3 morphology blasts and immunophenotypic features showing overlap between a precursor and mature B‑cell neoplasm.