MME and Burkitt lymphoma: With the B-cell characterization panel (panel 3 in Table S2) three B-cell lymphoma samples showed surface membrane (Sm)Ig light chain restriction (2 cases SmIgλ+ and one SmIgκ+) together with a Tdt+, CD20+hi, CD38+hi, CD10+hi, cyBcl2− immunophenotype which is highly characteristic of childhood Burkitt lymphoma, except for TdT expression.