Paget Disease of the Calvarium: A Case Report

Paget disease of bone (PDB) is a focal skeletal disorder characterized by excessive and disorganized bone remodeling. When the skull is involved, the disease may also affect the temporal bones. We present the case of a 68-year-old woman referred for evaluation of persistently elevated alkaline phosphatase (ALP), ultimately diagnosed with Paget disease of the calvarium with bilateral temporal bone involvement. The diagnosis was established through a systematic workup spanning nearly four years, including serial biochemical monitoring, exclusion of alternative causes of increased bone turnover, whole-body bone scintigraphy, skull radiographs, and computed tomography of the skull. Total ALP remained persistently elevated, and the bone-specific fraction rose progressively over the course of follow-up while calcium and parathyroid hormone remained within their reference ranges. She was treated with a single intravenous infusion of zoledronic acid. This case highlights the importance of serial monitoring of bone-specific ALP in the evaluation of persistently elevated ALP, the potential for subtle, easily overlooked bone scintigraphy findings in early or evolving Paget disease, and the role of multimodality imaging in defining the extent of calvarial and temporal bone involvement.