Extralymphatic involvement in diffuse non-Hodgkin's lymphoma.

Between 1961 and 1982, 543 patients with diffuse histiocytic, mixed, or undifferentiated lymphoma were treated at Stanford University, Stanford, Calif. Of this group, 281 (52%) had extralymphatic lesions and the 111 patients with stage IE and IIE disease were subjected to analysis. Most patients (94) had diffuse histiocytic lymphoma. Lymphangiography was performed in 77%, bone marrow biopsy in 91%, and diagnostic or staging laparotomy in 52% of the patients. All but five patients were treated with megavoltage irradiation and 35 patients received combination chemotherapy. Median follow-up was 4.0 years. Kaplan-Meier actuarial survival at five and 10 years was 46% and 36%, respectively. Freedom from relapse (FFR) at five years was 49% with no relapses beyond that point. The most common extralymphatic sites were the gastrointestinal tract, the head and neck region, and the lung. Prognosis could not be correlated with the specific sites of involvement. Patients with bulky disease (greater than 10 cm) or more than three sites of involvement had a significantly lower survival and FFR. There was no significant difference in outcome for patients treated with irradiation or combined modality therapy. Most patients (62%) relapsed in distant extralymphatic sites.