The evaluation of human lymph nodes, using plastic sections and enzyme histochemistry

The histopathologic evaluation of the human lymph node is frequently difficult. Although immunologic markers have been used recently in such evaluations, enzyme histochemical markers have been used only sporadically since their introduction in the 1930s. One reason that they have been neglected is that they have required the use of frozen sections. This article describes the use of a plastic embedding technic with enzyme histochemistry in a series of more than 300 reactive human lymph nodes. Enzyme histochemical reactions were preserved very well and could be localized extremely well with this technic, which allowed the identification of histologic features not readily apparent by other means. The technic may be valuable in evaluating both reactive and neoplastic lymph nodes.