Mandibular Osteitis Leading to the Diagnosis of SAPHO Syndrome

Abstract

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a disorder characterized by pustular skin lesions and osteoarticular lesions. Mandibular involvement of SAPHO syndrome is clinically rare, and it is difficult to reach a diagnosis of SAPHO syndrome from only mandibular manifestations. This report describes the case of a 26-year-old woman who presented with mandibular osteitis. Orthopantomogram and computed tomography showed sclerotic change of the right body of the mandible with periosteal reaction without odontogenic infection, which suggested the possibility of SAPHO syndrome. Detailed medical interview found that she had a history of palmoplantar pustulosis treated at a local dermatology clinic and additional bone scintigraphy showed diffuse increased uptake in the right mandible, as well as in the sternum and the sternocostoclavicular joints. She was eventually diagnosed as having SAPHO syndrome. We should consider SAPHO syndrome when we encounter a patient with mandibular osteitis of unknown etiology.

Figure 1

Orthopantomography. Sclerotic changes are seen in the right body of the mandible with periosteal reaction (arrows).

Figure 2

CT scan of the mandible. Axial (a) and coronal (b) and oblique sagittal reconstruction (c) plain CT images show sclerotic change and periosteal reaction in the right body of the mandible (arrows). Spotted osteolysis is also seen mainly in the cortical bone (arrowheads).

Figure 3

MR imaging of the mandible. Axial (a) and coronal (c) T1-weighted images and axial T2-weighted image (b) show thickening of the right mandible (arrows) and decreased bone marrow fat signal (arrowheads). Coronal short tau inversion recovery image (d) shows high signal intensity in the right body of the mandible (arrow), with perilesional soft tissue swelling (arrowhead).

Figure 4

Bone scintigraphy. There is increased tracer uptake in the right mandible (arrow), sternum, and the sternocostoclavicular joints (dotted circle).

Figure 5

Histopathological findings of the mandible. Enlarged and sclerotic bone trabeculae with little inflammatory cell infiltration [hematoxylin-eosin staining; magnification: 100× (a), 400× (b)].