Extremity pain in a child: a case report of leukemia

Early clinical diagnosis of leukemia in a child is difficult. Leukemia must be considered in the differential diagnosis of extremity pain in children, especially if the "bone" pain is out of proportion to a suspected etiology. Initial laboratory studies, radiographs, and scintigraphy may be normal. Indistinct radiographic findings of periosteal reaction, osteolytic lesions, sclerotic lesions, osteopenia, or leukemic lines in a child older than two years should alert a physician to the possibility of leukemia. Clinical suspicion of leukemia should be piqued if bone scan results seem to be inconsistent with a suspected diagnosis or unanticipated sites of increased metabolic activity are found in the lower extremities. If leukemia is probable, a bone marrow aspiration may be needed to confirm the diagnosis.