CD4 and peripheral T-cell lymphoma, not otherwise specified: In a situation where CD3 is positive with undifferentiated morphology, there is a risk of confusion with a peripheral T-cell lymphoma and, in fact, Pan et al. reported some cases to have been misclassified as such [8]. In our case, the lambda light chain restriction confirmed the B-cell lineage despite the expression of two T-cell antigens: CD3 and CD4.