ELECTRON-MICROSCOPY IN THE DIAGNOSIS OF MALIGNANT-LYMPHOMA

The burgeoning of such techniques as immunocytochemistry, cytogenetics, and molecular biology in the investigation and diagnosis of lymphomas has appeared to downgrade the role of electron microscopy. The persistence and popularity, however, of a morphology-based classification for non-Hodgkin's lymphoma suggest that tools amplifying morphology beyond the light microscopy perspective will remain valuable. The ultrastructural subclassification of lymphomas is largely arbitrary, but electron microscopy has an important role in the diagnosis of tumors that remain undifferentiated at the light microscopy level. Ultrastructural assessment is best allied with the results of other investigations for the accurate diagnosis of lymphomas, and the findings have led to the redefining of some forms of lymphoreticular malignancies. This review examines the electron microscopic features of the major groups of lymphomas, highlighting entities for which ultrastructural studies have been most useful.