Bone presentation of non-Hodgkin's lymphoma: experience at the Royal North Shore Hospital, Sydney; highlighting primary bone lymphoma.

Background: Primary lymphoma of bone (PLB) is a rare form of extranodal lymphoma. Between 1975 and 1992 39 patients with lymphoma presenting in bone were seen at the Royal North Shore Hospital (RNSH), Sydney. Of these, 12 (31%) had truly localised disease (Stage IE).

Aims: Patients were studied retrospectively to determine the prognostic significance of bony involvement per se versus involvement of a single bony site, and to determine the impact of treatment modality on outcome.

Methods: The 39 patients were divided into three groups according to extent of disease; single osseous site (Stage IE), multifocal bone, and bone plus visceral and/or nodal disease. Kaplan-Meier survival curves were constructed, and five year actuarial survival stated. Cox regression analysis was used to determine hazard ratios. Overall survival was used as the end-point.

Results: A trend for better survival was noted with Stage IE disease. Multifocal and disseminated disease appeared to have a poorer outcome when assessed by hazard ratio, with a value of 3 (95% CI 0.87-10.4; p = 0.08), compared to unifocal disease. Radiotherapy alone was as effective as combined modality treatment although patient numbers were too small for statistical confirmation.

Conclusions: The stage of lymphoma, rather than bony involvement per se, seems to have more prognostic importance. Radiotherapy alone offered equivalent results to combined modality treatment in this series.