Anti-Lambda detects surface immunoglobulin on normal and neoplastic B-cells. Lambda staining is seen in B-cell follicles of human lymphoid tissue. When dealing with B-cell neoplasms, the determination of light chain ratios remains the centerpiece. This is sound reasoning because most B-cell lymphomas express either kappa or lambda light chains, whereas reactive proliferations display a mixture of kappa and lambda positive cells. If only a single light chain type is detected, a lymphoproliferative disorder is very likely. Monoclonality is determined by a kappa-lambda ratio of greater than or equal to 3:1, a lambda-kappa ratio greater than or equal to 2:1 or a monoclonal population of 75% or more of the total population.