SAPHO Syndrome Mimicking Infectious Spondylodiscitis and Bone Metastasis

Area of Science:

• Rheumatology
• Orthopedics
• Dermatology

Background:

• SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome presents with complex osteoarticular and skin manifestations.
• Diagnostic challenges arise from atypical clinical presentations and varied disease patterns.

Observation:

• Case 1: A woman with cervical pain and an ivory vertebra, initially lacking typical SAPHO signs, showed manubrial sclerosis and a 'bullhead' scintigraphy pattern.
• Case 2: A woman with suspected infectious spondylodiscitis, negative biopsies, and MRI findings, was diagnosed with SAPHO based on bone scintigraphy.
• Case 3: A man with lung adenocarcinoma incidentally found to have osteosclerosis and sacroiliac joint changes, diagnosed with SAPHO after excluding malignancy via imaging.

Findings:

• Imaging findings, including X-ray, CT, MRI, and bone scintigraphy, were pivotal in diagnosing SAPHO syndrome across diverse presentations.
• The characteristic 'bullhead' appearance on bone scintigraphy and specific vertebral/sternal changes were key diagnostic indicators.
• Imaging successfully differentiated SAPHO syndrome from other conditions, including neoplasia and infectious spondylodiscitis, in these complex cases.

Implications:

• Radiological assessment is essential for the early and accurate diagnosis of SAPHO syndrome, especially in non-classic scenarios.
• Utilizing a combination of advanced imaging modalities can improve diagnostic confidence and differentiate SAPHO from mimics.
• This study highlights the utility of imaging in managing SAPHO syndrome, guiding appropriate clinical management and treatment strategies.