Long-term clinical outcome of spinal Langerhans cell histiocytosis in children.

Spinal involvement of Langerhans cell histiocytosis (LCH) affects morbidity, but outcomes are not well understood. We analyzed long-term outcomes following uniform treatment at a single institution. Clinical characteristics and outcomes of spinal LCH patients were retrospectively analyzed. Height ratios were calculated using the anterior height of the involved vertebral body on magnetic resonance imaging (MRI) and the expected normal vertebral height. Twenty-two (22.4%) of 98 patients diagnosed with LCH had spinal involvement. The median age at diagnosis was 4.1 (range 0.6-12.3) years. Thirty-one spinal lesions were identified in 22 patients; the thoracic spine (n = 17) was most commonly affected. Eight lesions with minimal collapse, which appeared normal on plain radiography, were detected with MRI. All patients received vinblastine-based chemotherapy. Fourteen (70%) of 20 evaluable vertebral body collapses, including eight severe lesions, showed improvement in vertebral body height at a median follow-up of 6.0 (range 2.8-12.0) years. All traceable patients were alive without disease. Long-term follow-up of vertebral body collapse revealed vertebral height improvement in approximately 70% of spinal LCH patients, even in severe cases. MRI at diagnosis detected spinal lesions earlier with higher sensitivity than plain radiography.