IS case 467: SAPHO syndrome

Mary Fontanella, MD

University of Rochester


Imaging Sciences URMC 2010
Publication Date: 2010-08-30

History

Patient is a 10-year-old female with previously diagnosed right clavicular mass. Patient subsequently underwent debridement with specimen pathology showing reactive changes. Additional history included acne.

Findings

Expansile, mixed lytic and sclerotic lesion with lamellated periosteal reaction in the proximal and middle third of the right clavicle.

Diagnosis

SAPHO syndrome

Discussion

SAPHO syndrome is a rare disorder manifested by synovitis, acne, palmoplantar pustulosis, hyperostosis, and osteitis. It is predominantly a disease of young and middle aged adults, but can also affect children. Pathogenesis of this syndrome remains unknown; bacterial (propionibacterium acnes) or viral infection and autoimmune disease have been suggested as possible causes. However, in most cases, neither infectious agents nor immune complexes or autoantibodies are isolated. Pathologic examination from the bone lesions shows nonspecific inflammatory changes indistinguishable from chronic osteomyelitis. One or more sites can be involved. With regard to the bony lesions, the sternocostoclavicular region is the most frequent site of the disease and is affected in 70%-90% of patients, with the region of the costoclavicular ligament, most frequently involved. Manifestations in this area include abnormal ossifications and erosions. The spine is the second most common site of the disease with involvement in about one-third of patients. In the spine, there are three radiographic manifestations, which are often present in combination; osteosclerosis of one or more vertebral bodies, paravertebral ossifications, and lesions of the diskovertebral junction. Sacroiliitis can occur. Involvement of the long bones occurs in approximately 30% of patients and predominantly affects the metaphyseal regions of the distal femur and proximal tibia, but the fibula, humerus, radius, and ulna can also be involved. The lesions often appear aggressive, consisting of osteosclerosis or osteolysis and periosteal new bone formation. These skeletal lesions, especially at the sternocostoclavicular site, with palmoplantar pustulosis or acne are highly characteristic but not pathognomonic of SAPHO syndrome. Diagnosis is additionally difficult if the sites of involvement are atypical, or if the patient is free of skin disease, and because there can be a delay of several years between cutaneous and skeletal lesions. In these cases, biopsy of the bone lesions and follow- up over several years may allow confirmation of the diagnosis of SAPHO syndrome. The main differential diagnoses are infectious osteomyelitis or spondylitis, osteosarcoma, Ewing sarcoma, metastasis, Paget disease, and aseptic necrosis of the clavicle.

References

  1. Cotten A, Flipo RM, Mentre A, et al. SAPHO syndrome. Radiographics. 1995 Sep;15(5):1147-54. PMID: 7501856

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