Paget's Disease of Bone Affecting Peripheral Limb: Difficulties in Diagnosis: A Case Report.

In terms of management of Paget's disease of bone (PDB), early diagnosis and proper management achieving remission is essential with lifelong specialist follow-up. We present the case of a 40-year-old woman with PDB affecting mainly the distal extremities (ankle and wrist). The patient visited our hospital in 2012 with heel pain. Plain radiography revealed osteoporosis, and a bone scan revealed hot uptake. Initial laboratory investigations showed normal serum calcium, 25-hydroxy-vitamin D, and parathyroid hormone levels; however, osteocalcin, C-terminal telopeptide of type I collagen, and bone alkaline phosphatase levels were elevated. A bone mineral density scan showed T- and Z-scores of -2.5 and -2.7, respectively, and bisphosphonate treatment was initiated. Biopsy performed on the calcaneal lateral wall revealed inconclusive findings. Follow-up biopsy on the left distal radius was performed 7 years later to investigate wrist pain, and this examination led to a final diagnosis as PDB. We suggest inconclusive biopsy result during the early phase of PDB and highly recommend follow-up evaluation in osteoporosis with atypical behavior.