Therapy for primary non-Hodgkin's lymphoma of bone and a comparison of results with Ewing's sarcoma.  Ten years' experience at the Istituto Ortopedico Rizzoli. 
The authors report on the results obtained in 30 consecutive cases of primary non-Hodgkin's lymphoma of bone (PNHLB) treated at the Istituto Ortopedico Rizzoli between 1972 and 1982.  Four patients were treated with radiotherapy only and 26 were treated with radiotherapy plus adjuvant chemotherapy.  At a median follow-up of 86 months (range, 30-160), among the 26 patients treated with chemotherapy also there were 3 relapses (2 had meningeal involvement and 1 had recurrence in another bone).  Relapse (local recurrence plus multiple new localizations) was observed in one of the four patients treated with radiotherapy only.  These results are compared with the results of 68 patients with Ewing's sarcoma who were treated during the same period with radiation therapy and adjuvant chemotherapy and reported in a previous study.  In this group, the disease-free survival rate was only 32% (20/68) with a much higher incidence of local recurrence (31%).  The necessity of making a clear distinction between PNHLB and Ewing's sarcoma is discussed.