Imaging manifestations and its clinical significance in patients with synovitis acne pustulosis hyperostosis osteomyelitis syndrome

Objective: To describe the clinical and imaging manifestations of patients with synovitis acne pustulosis hyperostosis osteomyelitis (SAPHO) syndrome, and to analyze the diagnostic importance of different clinical and imaging manifestations for SAPHO syndrome. Methods: Seventeen patients (7 males and 10 females) with SAPHO syndrome were recruited in this study. Age ranged from 36 to 67 years with a mean age of (48 ± 8) years. All patients fulfilled the diagnostic criteria of Benhamou. Serum HLA B27 antigen records were reviewed for all patients. Imaging data of the abnormal bone sites were collected by conventional radiograph in all patients, CT in 13 patients as well as MR in 3 patients. Average time to take for a definite diagnosis of the syndrome was 3.7 years (ranged from O.5 to 13 years). Results: Serum HLA B27 antigen was positive in all patients. Both skin and bone abnormalities were found in all patients. Ten patients had skin palmoplantar pustulosis and two patients had acne. Involving sites of bone and joints include sacroiliac joints, anterior chest and limbs. Sacroiliac joints were asymmetrically involved with imaging features in all patients. Eight patients exhibited anterior chest wall involvement. Five patients had osteomyelitis at limbs. For all images of 17 patients, CT was superior to conventional radiography in detecting abnormal changes of bone erosion and soft tissue swelling. MR imaging was able to depict edema changes that was not detectable by CT and radiography. Conclusion: SAPHO syndrome is a rare disease, but for patients with skin and bone-joint abnormalities, especially with skin palmoplantar pustulosis, acne as well as with imaging features at the sacroiliac joint and anterior chest wall, SAPHO syndrome should be taken into a diagnostic consideration. (authors)