Diffuse large cell and undifferentiated lymphomas with prominent mediastinal involvement.

This report describes 11 adults with non-Hodgkin's lymphoma who presented with symptoms caused by large mediastinal masses. Patients with lymphoblastic lymphoma were excluded from this analysis. Most of the patients were young women with localized disease at presentation. Ten tumors were diffuse large cell ("histiocytic") lymphomas and one was a diffuse, undifferentiated lymphoma, non-Burkitt's type. According to the Lukes' and Collins' classification scheme, seven were large cleaved cell type, three were large noncleaved and one was small noncleaved cell type. Sclerosis was present in four cases. Despite aggressive therapy nine patients died within 26 months of diagnosis and only two remain disease-free. Median survival of these patients was 16 months. Patients with symptomatic mediastinal masses and non-Hodgkin's lymphomas composed predominantly of large cell appear to share certain clinico-pathologic features and to present a poor prognosis subset of patients with non-Hodgkin's lymphoma.