A 48-year-old Japanese man with no remarkable medical history presented with pain and edema of both legs. Leg X-ray showed osteolysis and osteosclerosis, so-called cotton wool sign (Picture A). A technetium bone scan showed a marked uptake in the sternum, spine, sacroiliac bone, lower leg bone, and ankle joints (Picture B). His alkaline phosphatase level was 238 U/L. He was diagnosed with Paget disease of the bone (PDB), and administration of bisphosphonates was started, leading to remission. PDB is a bone metabolic disorder causing pain, fractures, and deformity. The prevalence of clinically diagnosed PDB is 0.3% in Caucasians over 55 years of age (1), but in Asian populations, the incidence is even rarer, especially in Japan, at 2.8 per million (2). Given that PDB can be easily overlooked, it is important to consider the possibility of PDB for the accurate diagnosis and treatment of patients showing cotton wool sign, a characteristic finding of PDB.
Picture.
The authors state that they have no Conflict of Interest (COI).
References
- 1. Nebot Valenzuela E, Pietschmann P. Epidemiology and pathology of Paget's disease of bone - a review. Wien Med Wochenschr 167: 2-8, 2017. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Hashimoto J, Ohno I, Nakatsuka K, et al. Prevalence and clinical features of Paget's disease of bone in Japan. J Bone Miner Metab 24: 186-190, 2006. [DOI] [PubMed] [Google Scholar]