Bone involvement in childhood acute lymphoblastic leukaemia.

This retrospective study evaluated the prognostic significance of the radiological signs of bony involvement in children with acute lymphoblastic leukaemia (ALL). The skeletal surveys of 52 children with ALL were reviewed for evidence of leukaemic involvement. Radiolucent metaphyseal bands, osteolytic lesions and periosteal reaction were considered signs of leukaemic changes. Twenty eight children had evidence of skeletal involvement of whom 14 had changes at three or more areas. Known risk factors such as age < 2 years and > 10 years, mediastinal lymphadenopathy, splenomegaly > or = 5 cm below the costal margin, a white cell count of > or = 20 x 10(9)/l and leukaemic blast cells in the cerebrospinal fluid at diagnosis occurred with equal frequency in children with and without skeletal changes as well as those children with signs of involvement at > or = 3 sites. Event free survival (Kaplan Meier analysis) also did not differ in these three categories of children. We concluded that bone involvement in childhood ALL is not associated with other risk factors and does not predict outcome per se.