Endocrine Abstracts

Introduction: Paget’s disease of bone is a chronic disorder of abnormal bone remodelling, often asymptomatic but occasionally presenting with pain, deformity, or reduced function. We describe a case of vertebral involvement diagnosed following isolated and persistently elevated alkaline phosphatase (ALP).

Case presentation: A man in his 60s was referred for investigation of longstanding ALP elevation, most recently 325 IU/l (reference range 35–129). Isoenzyme analysis confirmed a bone origin. Calcium, phosphate, parathyroid hormone, and vitamin D levels were normal. A 2017 skeletal survey showed only mild lumbar degenerative changes. In 2023, CT of the temporal bones revealed a retracted tympanic membrane. Whole-body bone scintigraphy in 2024 demonstrated increased uptake in the entire L4 vertebra and less marked uptake at T7, with cortical thickening and coarse trabeculation—findings consistent with Paget’s disease. The patient reported chronic back and leg pain with functional impairment and a history of musculoskeletal trauma. He also noted intermittent tinnitus and unilateral hearing changes, though no skull involvement was seen on imaging. There was no family history of metabolic bone disease. Based on biochemical and scintigraphic findings, a diagnosis of vertebral Paget’s disease was made. Intravenous zoledronic acid (5 mg) was recommended as first-line therapy, with counselling on possible side effects, including acute-phase reaction and the rare risk of osteonecrosis of the jaw. Adjunctive measures included analgesia, physiotherapy, and pre-treatment dental assessment.

Conclusion: This case highlights the importance of investigating isolated ALP elevation and the role of bone scintigraphy in detecting metabolically active disease. Timely diagnosis enabled appropriate management of a condition that may otherwise remain undetected until complications arise.

References: Ralston, S. H., & Corral-Gudino, L. (2022). Paget’s disease of bone. The Lancet, 400(10357), 1129–1142. https://doi.org/10.1016/S0140-6736(22)01363-5