Published online Nov 16, 2023. doi: 10.12998/wjcc.v11.i32.7785
Peer-review started: October 4, 2023
First decision: October 9, 2023
Revised: October 14, 2023
Accepted: October 30, 2023
Article in press: October 30, 2023
Published online: November 16, 2023
Processing time: 42 Days and 20.4 Hours
Osteomalacia (OM) is frequently confused with various musculoskeletal or other rheumatic diseases, especially in patients with adult-onset widespread musculoskeletal pain because of its low prevalence and non-specific manifestations.
To facilitate the early diagnosis and etiology-specific treatment of adult-onset hypophosphatemic OM.
A retrospective review of medical records was performed to screen adult patients who visited a physiatry locomotive medicine clinic (spine and musculoskeletal pain clinic) primarily presenting with widespread musculoskeletal pain at a single tertiary hospital between January 2011 and December 2019. We enrolled patients with hypophosphatemia, high serum bone-specific alkaline phosphatase levels, and at least one imaging finding suggestive of OM.
Eight patients with adult-onset hypophosphatemic OM were included. The back was the most common site of pain. Proximal dominant symmetric muscle weakness was observed in more than half of the patients. Bone scintigraphy was the most useful imaging modality for diagnosing OM because radiotracer uptake in OM showed characteristic patterns. Six patients were diagnosed with adefovir (ADV)-induced Fanconi syndrome, and the other two patients were diagnosed with tumor-induced OM and light-chain nephropathy, respectively. After phosphorus and vitamin D supplementation and treatment for the underlying etiologies, improvements in pain, muscle strength, and gait were observed in all patients.
Mechanical pain characteristics, hypophosphatemia, and distinctive bone scintigraphy patterns are the initial diagnostic indicators of adult-onset hypophosphatemic OM. ADV-induced Fanconi syndrome is the most common etiology of hypophosphatemic OM in hepatitis B virus-endemic countries.
Core Tip: This retrospective study assessed the clinical manifestations as well as laboratory, and imaging findings of patients with adult-onset hypophosphatemic osteomalacia (OM) to highlight the importance of early diagnosis and etiology-specific treatment. Physicians should consider OM as a possible cause of widespread musculoskeletal pain in adult patients. Mechanical pain characteristics, insufficiency fracture sites, distribution of muscle weakness, hypophosphatemia, and distinctive patterns on bone scintigraphy can be the initial diagnostic indicators. Adefovir-induced Fanconi syndrome, phosphaturic mesenchymal tumors, and light-chain nephropathy can cause hypophosphatemic OM.