FDG PET/CT in Early and Late Stages of SAPHO Syndrome: Two Case Reports With MRI and Bone Scintigraphy Correlation.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare disease, which may be underdiagnosed or misdiagnosed because of nonspecific clinical and imaging findings. We present 2 cases of SAPHO syndrome with MRI, bone scintigraphy, and FDG PET/CT findings. In case 1 with early-stage disease, the active osteitis showed osteolytic bone destruction with increased FDG uptake. In case 2 with late-stage disease, the inactive bone lesions presented as osteosclerosis with normal FDG uptake. Familiarity with the FDG PET/CT findings of SAPHO syndrome in different stages may be helpful for correct diagnosis.