A 74-year-old patient was incidentally diagnosed with SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis) syndrome after a low-dose computed tomography (LDCT) performed for lung cancer screening purposes demonstrated characteristic bone abnormalities in the anterior chest wall. The patient suffered for decades from mild idiopathic recurrent palmoplantar pustulosis (Fig. 1A), but had not been diagnosed with SAPHO syndrome until a multidisciplinary rheumatology–dermatology consultation (suggested by the radiologist in the LDCT report) led to the diagnosis of a mild and incomplete clinical–radiological form of the syndrome. LDCT demonstrated hyperostosis of the upper sternal manubrium associated with hyperostosis, osteosclerosis, and ankylosis of the first chondrosternal joints (Fig. 1B–E), but with sparing of both sternoclavicular joints. A technetium-99m bone scintigraphy confirmed avid bilateral tracer uptake by the first chondrosternal joints (Fig. 1F). The patient was treated with nonsteroidal anti-inflammatory drugs and topical medications with a good response to treatment. SAPHO syndrome encompasses a heterogeneous spectrum of clinical and imaging findings, including osteitis and hyperostosis, frequently involving the anterior chest wall, and variably associated cutaneous manifestations such as acne or palmoplantar pustulosis. Importantly, the clinical–radiological presentation may be incomplete or atypical, with some patients lacking characteristic symptoms or imaging findings at the time of diagnosis. To our knowledge, this is the first report of a SAPHO syndrome incidentally detected on LDCT performed for lung cancer screening purposes.
(A) Picture shows pustules and thick scales involving the sole of the left foot. (B, C) Axial (B) and coronal (C) low-dose chest CT images (bone window) show hyperostosis and ankylosis of the first chondrosternal joints (long arrows) as well as osteosclerosis and cortical irregularity of the manubrium (short arrows). (D, E) Sagittal oblique chest CT images show the first chondrosternal joints (D corresponds to the right joint whereas E corresponds to the left one); note the hyperostosis of both chondrosternal joints (long arrows), the cortical irregularity of the manubrium (short arrows), and the minimal involvement of the sternoclavicular joints. (F) Bone scintigraphy of the thorax (anterior view) shows intense radiotracer uptake by the first chondrosternal joints and upper manubrium (arrows).
All authors contributed equally to the manuscript writing. L.G. selected and edited the radiological images. All authors provided input to the final version of the manuscript.
Ethical considerationsThis article does not involve any studies on human participants conducted by the authors.
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Artificial intelligence involvementThe authors declare that they have not used any type of generative artificial intelligence for the writing of this manuscript, nor for the creation of images, graphics, tables, or their corresponding captions.
FundingThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Conflicts of interestThe authors declare not to have any conflicts of interest that may be considered to influence directly or indirectly the content of the manuscript.
