SAPHO syndrome in the differential diagnosis of metastasis.

SAPHO syndrome was proposed in the late 80s in order to group different osteoarticular manifestations with specific radiological findings such as the hyperostosis of the front part of the chest wall. Prevalence, etiology and pathogenesis of the disease are unknown, while diagnosis is made both clinically and by the specific gammagraphic image of «bull horn» in the sternoclavicular joint. The following case of a 64-year-old woman diagnosed with infiltrating ductal carcinoma of the right breast pT1N0Mx is reported. When studying the extent of the disease, a gammagraphic image of diffuse blast injury in the sterna manubrium was evidenced, which allowed the suspicion of Paget's disease or metastatic injury. Study was completed with a chest CT in which manubrium sclerosis was evidenced, suggesting metástasis. Res ults of the studies pointed out SAPHO syndrome as the most likely diagnostic option. The low tumor stage of the patient prompted the idea of possible alternative diagnoses. A deeper knowledge of this clinical condition may be crucial to avoid mistakes when classifying a subject in more advanced tumor stages, and consequently, to prevent the use of more aggressive chemotherapy and radiotherapy treatments.