Langerhans cell histiocytosis of the spine in children. Long-term follow-up.

Abstract

Langerhans cell histiocytosis causes destructive lesions in a child's spine. Few large, long-term studies have evaluated the clinical and radiographic presentation, natural history, outcomes of modern treatment approaches, and maintenance of normal spinal growth and stability after the diagnosis of this disease in children. Twenty-six children with biopsy-proven Langerhans cell histiocytosis involving the spine were treated at our institution between 1970 and 2003. They had a total of forty-four involved vertebrae (twenty cervical, fourteen thoracic, and ten lumbar). Vertebral body collapse was measured on radiographs and classified as grade I (0% to 50% collapse) or grade II (51% to 100% collapse) and subclassified as A (symmetric collapse) or B (asymmetric collapse). Lesions of the posterior elements of the spine were classified as grade III. Twenty-three children were followed for two years or more (mean, 9.4 years), and the analyses of treatment and long-term outcomes were performed in that group of patients. There was a predominance of lesions in the cervical spine (p </= 0.02). Sixteen (62%) of the twenty-six children were found to have multifocal skeletal disease. Cervical and lumbar lesions were more commonly associated with multilevel spinal disease. The extent of the initial collapse seen radiographically was grade IA for twenty vertebrae, IB for three, IIA for ten, IIB for nine, and III for two. Grade-I lesions were more likely to be associated with symmetric collapse than were grade-II lesions. Spinal deformity developed in four children, and two later required spinal fusion. No relationship was observed between the grade of the initial collapse and the subsequent development of spinal deformity. Despite heterogeneous treatment, all patients were alive and well with resolution of all presenting signs and symptoms and no evidence of active disease at the time of the most recent follow-up. We found a particularly high prevalence of lesions in the cervical spine and a high prevalence of multiple skeletal lesions. In contrast to the classic finding of vertebra plana, we found that more severe lesions often led to asymmetric collapse; yet, asymmetric collapse was not found to be associated with the development of subsequent spinal deformity. The natural history of these lesions in the spine in the absence of systemic disease or spinal deformity is such that aggressive surgical management is usually not indicated; only follow-up is necessary to monitor recovery and spinal balance.