A surgical case of abscess of the sternal region due to synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome

Abstract

Abstract Background Synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome is a rare chronic inflammatory disorder characterized by cystic skin disease, aseptic osteomyelitis, and hyperostosis. It is rarely associated with subcutaneous abscesses in the anterior chest wall. Herein, we describe a case of a sternal abscess due to SAPHO syndrome that was successfully treated with debridement. Case presentation A 62-year-old female patient presented with a chief complaint of a mass in the right anterior chest region. Computed tomography showed the presence of an abscess around the sternum. Magnetic resonance imaging revealed inflammation of the spine. The patient also had a history of palmoplantar pustulosis, raising the suspicion of SAPHO syndrome; however, sternoclavicular joint infection could not be excluded. Abscess drainage and wall debridement were performed. However, reaccumulation of the abscess occurred early after surgery. Although culture tests of the abscess were negative, histopathological examination of the abscess wall revealed a tuberculoid granuloma. Owing to unsuccessful open wound management, debridement of the anterior thoracic skin and abscess wall and partial sternal resection were performed 2 months after the initial surgery. Negative-pressure wound therapy (NPWT) was applied for 4 weeks after surgery, followed by immunosuppressant administration. The patient underwent split-thickness skin grafting on postoperative day 65 and had no abscess recurrence at 18 months post-surgery. Conclusions Abscesses in the sternal region caused by SAPHO syndrome can be difficult to differentiate from infectious arthritis. Therefore, drainage and debridement should be considered if infection cannot be excluded.