Enzyme histochemistry on normal and pathologic paraffin-embedded lymphoid tissues

So far, enzyme histochemical examination has been applied, with few exceptions, either to tissue imprints or to cryostat sections of freshly collected samples. This procedure is not easily applicable in routine histopathologic examination. In this study, a simplified tissue embedding procedure is presented which can be performed using an automatic tissue changer. The paraffin embedded samples can be used for both conventional histopathologic examination and for demonstrating enzymes in sections. The enzymes studied (alkaline phosphatase, alpha-naphthyl acetate esterase, acid phosphatase, tartrate resistant acid phosphatase, ATPase, peroxidase, and chloroacetate esterase) gave comparable results in formalin-fixed cryostat sections and paraffin sections in both normal and pathologic lymphoid samples. The only exception was ATPase, which could not be demonstrated on paraffin-embedded material. The technic described has broad application in the analysis of lymphoid diseases.