374 HYPERTROPHIC OSTEOARTHROPATHY IN CHILDREN WITH LEUKEMIA

Abstract

Bone lesions are frequently encountered in children with leukemia as part of their disease or occasionally as consequence of therapy. While leukemic infiltration is a well known cause of bone pain in children, avascular necrosis and osteoporosis can also be responsible for these complaints. The authors present two children with an unusual cause of bone pain in childhood leukemia, hypertrophic osteoarthropathy (HOA). This condition is well known in adults, but is rarely seen in children. The most frequently associated conditions in children are chronic lung, liver or heart disease and sometimes malignant or benign tumors. In a child with acute non-lymphoid leukemia (ANLL) FAB type M7 and in a child with common acute lymphoid leukemia (ALL) - both in the maintenance phase of therapy - bone pain developed. The radiographs showed cortical thickening and periosteal new bone formation along the diaphyses of the long bones. Bone scintigraphy remained negative. MRI showed no signs of residual leukemic infiltration. Both children were in remission at the time of detection of the bone lesions, and did not have any signs of chronic infection. Approximately three months later however - although the bone pain disappeared - the child with ANLL developed a myelodysplastic syndrome (MDS) and the patient with ALL a partial relapse with 12 % blasts in the bone marrow. The occurrence of HOA in children with leukemia, both ANLL and ALL. should instigate repeated bone marrow investigation since it might herald MDS or relapse.