Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis (SAPHO) Syndrome Mimicking Bone Metastases in the Spine: A Presentation of Two Cases and Literature Review

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome is a rare disorder of unknown etiology with heterogeneous clinical manifestations. We describe two cases of patients diagnosed with SAPHO syndrome mimicking spinal bone metastases. A literature review was conducted to identify similar previously reported cases. The first patient was a 56-year-old woman with progressive back pain for six months who was referred to the neurosurgery department for suspected spinal metastases. A spinal CT scan revealed hyperdense lesions at T10 and hyperdense changes in the lumbar vertebrae. Spinal MRI demonstrated bone marrow edema that was hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging in multiple thoracic vertebrae, and the PET/CT showed multiple skeletal lesions affecting the spine with low-to-moderate