Detection of lymphocyte antigens in tissues placed in transport medium. Comparison with cryostat fresh-frozen section technic. An immunologic study of 56 cases.

It has been suggested recently that use of a transport medium (Michel's medium) satisfactorily preserves the antigenicity of surface markers on lymphocytes for immunologic evaluation. Transport medium has been reported to be especially useful when immediate preparation of a specimen for immunologic study is not possible. Because adverse conditions such as changes in temperature during the transport of fresh-frozen tissue may markedly alter immunologic markers, it is desirable to transport fresh tissue in a medium that does not adversely affect the immunoreactivity of the tissue antigens. Therefore, we undertook a comparative study in which we compared cryostat-cut, fresh-frozen sections and tissues fixed in transport medium. The specimens were obtained from 56 consecutive patients who had various malignant lymphomas and benign lymphoid disorders. The results of our study indicate that the morphologic and immunologic findings obtained from the frozen sections that had been maintained in the transport medium (Michel's) may be confusing and may be interpreted inaccurately. This study also confirms our previous observation that the inconclusive or spurious results occasionally obtained with cell suspension technics can be avoided if the immunohistochemical technics are applied to cryostat-cut, fresh-frozen sections. We conclude that immunohistochemical study of cryostat-cut fresh-frozen sections remains the technic of choice for the identification and evaluation of both the morphologic and immunologic characteristics of tissues involved by lymphoproliferative diseases.