Skeletal manifestation of non-Hodgkin's lymphoma in pediatric patients

Purpose. Skeletal manifestation of Non-Hodgkin's lymphoma is rare in pediatric patients. Objective of the study was to determine imaging features, before and after treatment, and to correlate these features with clinical outcome. Methods. A retrospective analysis of 1246 patients from two therapy studies (NHL-BMF-90 and 95) was performed. Imaging studies of 63 patients with bone involvement of lymphoma were reevaluated. Results. Incidence of initial bone involvement in Non-Hodgkin's lymphoma was 6.8%. Distribution was best assessed by bone scan, MRI revealed larger areas of marrow involvement and detected additional lesions. Sites of prediliction were long bones of the lower extremities with epiphyseal involvement in 39%. Residual signal alterations in MRI after successful therapy remained in 77%. Osteonecrosis after therapy was a common finding. Clinical outcome war not correlated to the presence of bone involvement. Conclusions. Since clinical outcome is not effected by bone involvement in childhood NHL, value of screening may be limited. Knowledge of imaging characteristics is mandatory for initial evaluation of primary osseous lymphomas and symptomatic lesions as well as for therapy controls.