SAPHO syndrome masquerading as metastatic bone disease

A 46-year-old woman who had had a right mastectomy for breast carcinoma a month before underwent bone scintigraphy. The examination revealed multiple pelvic, vertebral and sternal hot spots suggestive of bone metastases. Standard X-rays and CT confirmed the presence of bony lesions but they were not typical of bone metastases. As the radiographic appearance was reminiscent of SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteitis), bone biopsies were performed. Histology showed fibrosis and hyperostosis but no tumour cells. On further questioning, the patient revealed she had had palmar pustulosis and sacroiliitis some years earlier. The purpose of the case report is to show that accurate diagnosis of SAPHO syndrome requires careful clinical and radiological examinations.