Eosinophilic granuloma of the spine is a common benign disease in children and adolescents that rarely affects adults.This article describes the case of a 32-year-old woman with a solitary eosinophilic granuloma presenting as a local lytic lesion at the L4 vertebral body. She presented with a 2-month history of low back pain without neurological deficits. Plain radiographs showed a lytic lesion of the L4 vertebral body. Computed tomography scans showed an osteolytic lesion surrounded by partial sclerotic change of the L4 vertebral body. Magnetic resonance imaging revealed a low-intensity lesion on T1-weighted images and a high-intensity lesion on T2-weighted images. A computed tomography-guided transpedicular needle biopsy of the L4 vertebral body was performed. The histological specimen stained with hematoxylin-eosin revealed features of eosinophilic granuloma with aggregates of Langerhans cells. On immunological studies, the diagnosis of eosinophilic granuloma was facilitated by diffuse immunoreactivity of S-100 protein and CD1a. For the 3-month period after biopsy, the patient was fitted with a corset and allowed to walk. Four months after biopsy, computed tomography scans showed that remodeling of the destructive lesion of the L4 vertebral body was occurring. Two years after initial onset, the patient had complete relief of low back pain and no neurologic deficit. Computed tomography scans showed full reconstitution of the lesion. This was a rare case of successful conservative treatment of eosinophilic granuloma of the lumbar spine in an adult. Conservative treatment may be considered in a patient with an eosinophilic granuloma with no neurological deficit or spinal instability.
