Content area
Full Text
Introduction
Synovitis, acne, palmoplantar pustulosis, hyperostosis, and osteitis (SAPHO) syndrome was initially described as a disease of aberrant bones, joints and skin lesions in 1987 by Chamot et al (1). SAPHO syndrome can occur at any age and is characterized by repeated remission and recurrence, and it rarely occurs in individuals aged >60 years (2). Although a wide spectrum of clinical hallmarks have been previously described for SAPHO syndrome, the osteoarticular and/or dermatological lesions are the most important manifestations. Most patients present with local inflammatory pain, swelling, and limited movement at the site of the active lesions, particularly at the anterior chest wall (ACW) (3). The prevalence of SAPHO is <1/10000 (4). However, its actual prevalence may be underestimated due to incorrect diagnosis. High incidence rates of SAPHO syndrome have been reported in the European population (5), whereas only occasional cases are reported in Chinese individuals (6–8). Osteitis and hyperostosis are striking features that can be observed in any involved skeletal segments (9). It has been demonstrated that skin manifestations are detected in 63.5% of patients (4), whereas at least 15% adults never experience skin manifestations (10). Therefore, diagnosis of SAPHO syndrome may be difficult in certain cases, particularly if the dermatological manifestations are absent (10). The pathogenesis is poorly understood. However, it has been shown that persistent infection with low-virulence pathogens and the autoimmune process triggered by a bacterial or viral pathogen may be associated with SAPHO syndrome (10).
The present case study described the imaging features of three cases of SAPHO with sternoclavicular joint arthritis but without skin manifestations using multiple imaging modalities, including computed tomography (CT), magnetic resonance imaging (MRI) and bone scintigraphy. This study was approved by the Institutional Review Board of the Affiliated Hospital of Nanjing University of Chinese Medicine (Nanjing, China) with waiver of informed consent.
Case reports
Case 1
A 52-year-old male patient was admitted to the Affiliated Hospital of Nanjing University of Chinese Medicine due to progressive pain at the ACW in March 2008. Over the past 2 years he had recurrently suffered from sternoclavicular arthritis. Initially, the symptoms included swelling, pain, and muscle stiffness with no apparent causes. He was referred to another hospital, but no diagnosis was made and no treatment was administered. As the...