SAPHO Syndrome¶

Definition¶

SAPHO syndrome (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis) is a rare chronic inflammatory disorder characterized by osteoarticular and dermatological manifestations. Spinal involvement occurs in approximately 30–40% of cases, most commonly in the thoracic spine, and can mimic infection or tumor on imaging.

Imaging Findings¶

Spine¶

Vertebral body — Sclerotic lesion (hyperostosis) involving one or more vertebral bodies, often with adjacent endplate erosion
Paravertebral ossification — Bulky, non-marginal ossification that can mimic DISH or psoriatic syndesmophytes
Endplate erosions — Can mimic spondylodiscitis
Anterior chest wall — Hyperostosis of the sternoclavicular region is the most characteristic skeletal finding and is often present concurrently with spinal involvement

MRI¶

Vertebral body edema (low T1, high STIR) in acute phases
Sclerosis (low T1 and T2) in chronic phases
Enhancement during active inflammation

CT¶

Sclerosis and hyperostosis of affected vertebral bodies
Anterior chest wall involvement — sternoclavicular hyperostosis

Nuclear Medicine¶

Bone scan shows increased uptake at involved sites — the "bull's head" sign at the sternoclavicular region is characteristic

Clinical Pearl

When you encounter a sclerotic vertebral body lesion that mimics metastasis or lymphoma, look at the anterior chest wall — sternoclavicular hyperostosis on CT or bone scan is the clue to SAPHO syndrome. The combination of vertebral sclerosis + sternoclavicular hyperostosis + skin manifestations (palmoplantar pustulosis, severe acne) is virtually diagnostic.

Key Points¶

SAPHO is a chronic inflammatory disorder with skeletal and skin manifestations
Spinal involvement produces sclerotic vertebral lesions that can mimic tumor or infection
Sternoclavicular hyperostosis is the most characteristic finding — always check the anterior chest wall
"Bull's head" sign on bone scan at the sternoclavicular region
Thoracic spine is most commonly affected
Skin findings (palmoplantar pustulosis, acne) provide clinical context

References¶

McGauvran AM, Kotsenas AL, Diehn FE, et al. SAPHO syndrome: imaging findings of vertebral involvement. AJNR Am J Neuroradiol. 2016;37(8):1567-1572. https://pmc.ncbi.nlm.nih.gov/articles/PMC7960289/
Demirci Yildirim T, Sari I. SAPHO syndrome: current clinical, diagnostic and treatment approaches. Rheumatol Int. 2024;44(11):2301-2313. https://pubmed.ncbi.nlm.nih.gov/37889264/
Przepiera-Będzak H, Brzosko M. SAPHO syndrome: pathogenesis, clinical presentation, imaging, comorbidities and treatment: a review. Postepy Dermatol Alergol. 2020;38(6):937-942. https://pmc.ncbi.nlm.nih.gov/articles/PMC8802951/
Rukavina I. SAPHO syndrome: a review. J Child Orthop. 2015;9(1):19-27. https://pubmed.ncbi.nlm.nih.gov/25585872/
SAPHO syndrome. Radiopaedia.org. https://radiopaedia.org/articles/sapho-syndrome