Long-term follow-up of a case of Langerhans cell histiocytosis of the cervical spine with pulmonary involvement.

Unlike Langerhans cell histiocytosis (LCH) involving the skull, LCH of the vertebrae and lungs requires careful long-term follow-up because of the risks of motor and respiratory dysfunction; however, few reports have addressed this issue. A boy aged 7 years 7 months presented with bilateral shoulder pain and neck pain. Initial imaging revealed C6 vertebral bone lysis, a mass spanning C5-C7, C6 vertebral body flattening, and epidural extension. Chest radiographs and CT scans showed diffuse reticular and funicular shadows, ground-glass opacities, interlobular septal thickening, and swollen hilar lymph nodes. Bone scintigraphy showed cervical accumulation, while gallium scintigraphy revealed diffuse lung uptake. Lung biopsy confirmed LCH (CD1a, S-100, langerin positivity), confirming a diagnosis of multisystem LCH involving lung, bone, skin, and soft tissue. Treatment with cytarabine, vincristine, and prednisolone, in accordance with the Japan LCH Study Group-02 protocol, resulted in rapid respiratory improvement, withdrawal of oxygen, and resolution of neck pain. Seven years after completing chemotherapy, the patient had no neck discomfort and satisfactory cervical motion, normal respiratory function, and no respiratory symptoms. A cervical MRI scan at 1.5 years after the end of chemotherapy showed persistent C6 vertebral flattening from the compression fracture, which remained clinically stable throughout follow-up, with no herniation, mass formation, or epidural recurrence. Chest imaging at a 7-year follow-up examination showed no abnormalities. These findings suggest that timely diagnosis and appropriate chemotherapy yield favorable long-term outcomes in multisystem LCH with vertebral and pulmonary involvement, and avoid major sequelae.