Radiologic zebra line sign in a patient with Langerhans cell histiocytosis on bisphosphonate therapy

[摘要] A 3-year-old boy was diagnosed with multi-system Langerhans cell histiocytosis (LCH) with bone, skin, lung, lymph node, and bone marrow involvement at 8 months of age. He achieved non-active disease (NAD)after chemotherapy with prednisolone, vincristine, and cytarabine.However, the patient presented with bone lesion relapse. Despite reinitiation of vinblastine and prednisolone, his bone lesion progressed,prompting treatment with three cycles of cladribine. While it provided some improvement, he presented with bone lesion relapse soonafter cladribine therapy. Due to the recurrence of the bone lesion, weadministered bisphosphonate therapy using monthly zoledronic acidfor 6 months in addition to conventional chemotherapy, which resolvedhis bone lesion. The patient achieved NAD for 1 year. While he didnot present with bone pain, radiographs obtained during bisphosphonate therapy revealed a “dense metaphyseal band sign,” also known as“zebra line sign,” at the tibia and fibula (Figure 1A−D). Nevertheless,2 years after initiation of bisphosphonate therapy, his growth remainedsteady (Figure 1E).