European Task Force on Lymphoma project on lymphocyte predominance Hodgkindisease: histologic and immunohistologic analysis of submitted cases reveals 2 types of Hodgkin disease with a nodular growth pattern and abundant lymphocytes

Paraffin blocks and clinical data from 521 patients with lymphocyte predomi nance Hodgkin disease (LPHD) diagnosed between 1970 and 1994 were collected from 16 European and United States oncological centers to establish the pa thologic and clinical characteristics of a large patient cohort, to determi ne how frequent T-cell-rich large B-cell lymphoma (TCRLBCL) is among LPHD, and to find differential diagnostic criteria distinguishing between the 2 l ymphoma categories. For this purpose, conventionally and immunohistological ly stained sections were reviewed by a panel of hematopathologists, The dia gnosis of LPHD was confirmed in only 219 of the 388 assessable cases (56.5% ), This low confirmation rate was due mainly to the presence of a new varia nt of classical Hodgkin disease (CHD), which resembled, in terms of nodular growth and lymphocyte-richness, nodular LPHD and, in terms of the immunoph enotype of the tumor cells, CHD and was designated nodular lymphocyte-rich CHD (NLRCHD). The nodules of LRCHD consisted - as in nodular LPHD - predomi nantly of B cells but differed from those present in LPHD in that they repr esented expanded mantle zones with atrophic germinal centers. Clinically, p atients with LPHD and NLRCHD showed similar disease characteristics at pres entation but differed in the frequency of multiple relapses and prognosis a fter relapse. Patients with LPHD and NLRCHD clearly differed from patients with CHD with nodular sclerosis or mixed cellularity, as they presented wit h an earlier disease stage and infrequent mediastinal involvement. As 97% o f the LPHD cases showed a complete or partial nodular growth pattern, their differentiation from TCRLBCL was a rare problem in the present series, (C) 2000 by The American Society of Hematology.