Bone Health ECHO Case Report: Is it Paget's Disease?

A 54-year-old woman was referred by her rheumatologist for evaluation of an elevated serum alkaline phosphatase (ALP) in the setting of polyarthritis. The metabolic work-up was significant for an elevated bone fraction of alkaline phosphatase isoenzymes, and high bone turnover markers, including fasting C- telopeptide (CTX). A diagnosis of Paget's disease of bone (PDB) was considered. A whole-body nuclear bone scan showed diffuse increased uptake in the calvarium, suggestive of PDB, with no other localizing areas of increased uptake. Skull X-rays show mild sclerosis and medullary expansion of the posterior parietal bones and occiput, interpreted by the radiologist as unlikely to be PDB with a high level of uncertainty. Bone density testing with dual-energy X-ray absorptiometry showed low bone mass (osteopenia) with fracture probability that was below the treatment threshold. The case was presented and discussed on Bone Health ECHO, a virtual community of practice with the aim of enhancing global capacity to deliver best practice skeletal health care. The results of the discussion are presented here.