Utility of emergent plain X-ray for childhood acute leukemia with bone pain.

Background We aimed to evaluate the utility of plain X-ray radiograph (PXR) findings in suggesting a diagnosis of acute leukemia in children presenting with bone pain in the emergency department (ED) of a children's hospital. Methods Using our radiology reporting system and registered data for childhood acute leukemia, we collected data regarding patients who underwent musculoskeletal PXR examinations in the ED because of bone pain in their extremities from March 1, 2002 to June 30, 2015. We retrospectively reviewed their PXR findings and clinical information from the electronic medical records. Results A total of 1331 patients underwent PXR examinations and 12 among them had suspected acute leukemia from PXR findings. From the registered data, we found 12 acute leukemia patients who underwent emergency extremity PXR. Ten patients were finally confirmed to have acute leukemia by bone marrow examinations. The most common finding was lucent metaphyseal bands demonstrated in seven cases, whereas six patients did not show any abnormalities in their peripheral blood cell counts. Sensitivity and specificity values of PXR for acute leukemia diagnosis were 90.0% and 99.8%, respectively. Positive predictive value and negative predictive values were 75.0% and 99.9%. Conclusions PXR is a useful diagnostic tool to detect possible acute leukemia in patients presenting with bone pain earlier than abnormalities of their peripheral blood cell counts. Our results implied the possibility of having acute leukemia and re-examining PXRs more carefully, even when there are no abnormalities in blood cell counts.