Survival of patients with localized histiocytic lymphoma.

Twenty of 65 patients with diffuse histiocytic lymphoma were identified by staging laparotomy as being in pathologic stages (PS) I, I(E), II, II(E). Six of the 20 patients were treated with total nodal, 10 with extended mantle, and four with involved-field radiotherapy. The survival rate and relapse-free survival at five years were 71% and 78%, respectively. All relapses occurred within the first year and were confined to patients with PS II disease and four or more sites of involvement. Accurate pathologic staging identifies patients who are potentially curable with radiotherapy. Further studies are required to determine the treatment necessary to achieve cure in PS II patients with more than four sites of involvement.