Vertebral Sarcoidosis Mimicking Lytic Osseous Metastases

Abstract

Vertebral sarcoidosis is a rare condition that can present with persistent back pain, often with concurrent lung, lymph node, or skin involvement. It can produce lytic or blastic osseous lesions that are indistinguishable from metastatic cancer on bone scan and magnetic resonance imaging (MRI). It usually occurs at the time of initial diagnosis of sarcoidosis, but may in very rare cases appear many years after presumed resolution of thoracic sarcoidosis. We present the case of a 47-year-old man who developed persistent low back pain 16 years after spontaneous resolution of stage I pulmonary sarcoidosis. MRI of the spine showed lytic thoracic and lumbar vertebral lesions. Computed tomography of the chest showed a pleural-based lung mass, multiple pulmonary nodules, and hilar and mediastinal lymphadenopathy. Positron emission tomography with fluorodeoxyglucose was widely positive, including at the vertebral foci noted on MRI. Metastatic lymphoma was suspected, but mediastinal lymph node and vertebral body biopsies showed noncaseating granulomas with negative stains for acid-fast bacilli and fungi. After 1 month of treatment with prednisone, the angiotensin-converting enzyme level and erythrocyte sedimentation rate had normalized, and the back pain was substantially improved. We found only 1 case report of a longer interval between resolution of initial sarcoidosis and development of vertebral involvement.