Special problems in B-cell lymphoma: an historical perspective.

50 years ago (1958) The Rappaport Classification system for lymphomas had recently been introduced (1957). In that scheme, lymphomas were considered either nodular or diffuse and either well differentiated, poorly differentiated, undifferentiated, or mixed. The term histiocytic was introduced based upon the belief that neoplasms of large cells were derived from non-lymphoid cells. It is likely that a case of primary mediastinal lymphoma would have been called “diffuse histiocytic lymphoma,” a case of marginal zone lymphoma called “diffuse welldifferentiated lymphoma,” and a case of Burkitt lymphoma (which had just been described in 1957) called “diffuse undifferentiated lymphoma.” Available treatments in 1958 included a few alkylating agents (nitrogen mustard), anti-metabolites (methotrexate), and external beam radiotherapy. Treatment was largely palliative.