Thoracic spine Langerhans cell histiocytosis in a child with achondroplasia.

Multifocal bone Langerhans cell histiocytosis (LCH) is usually treated with prednisolone and vinblastine. We present a case conservatively treated with indomethacin with good clinical and radiological response. A 7-year-old achondroplastic boy presented with worsening thoracic back pain and leg weakness. An admission MRI spine showed a pathological T1 vertebrae fracture with posterior soft tissue extension compressing and distorting the spinal cord. A CT guided biopsy revealed an LCH. Steroids were avoided to reduce osteopenia risk and further vertebral fragility. Considering the risk of a thoracic surgical approach in a child with this background, he was managed conservatively with indomethacin and a Sternal Occipital Mandibular Immobilizer (SOMI) Brace. Pain resolved completely within 6 months and the brace was discontinued. Serial follow-up scans showed progressive resolution of the pathological T1 fracture and complete resolution of the spinal cord compression.