Detection of Bone Lesions in Langerhans Cell Histiocytosis

Abstract
This research was undertaken to determine the relative sensitivity of scintigraphic and radiographic bone survey examinations in detecting bone lesions in various regions of the skeleton in patients with a histopathologic diagnosis of Langerhans cell histiocytosis (LCH). Radionuclide skeletal scintigraphy (RNSS) and x-ray skeletal surveys (XRSS) of 42 children with a histopathologic diagnosis of LCH were evaluated retrospectively. Of the 191 lesions detected in 42 patients, 36 (19%) were missed on RNSS and 55 (29%) were missed on XRSS. Most of the missed lesions on RNSS were in the skull (26 of 36). XRSS also missed 13 skull lesions seen on RNSS. Most of the lesions missed on XRSS were in the ribs (20 of 30 rib lesions), whereas RNSS identified 29 of them. XRSS also missed 13 of 38 lesions in the spine and pelvis, while RNSS demonstrated all of them. Both modalities showed comparable sensitivity in the extremities. RNSS has a greater value in detecting sites of bone involvement with LCH than reported previously. RNSS is more sensitive than XRSS in detecting histiocytic lesions in the ribs, spine and pelvis and less sensitive in identifying lesions in the skull.