Surgical treatment as a key determinant of outcome in phosphaturic mesenchymal tumors of the bone and soft tissue: a systematic review and case series.

Purpose: Phosphaturic mesenchymal tumors (PMTs) are rare neoplasms causing tumor-induced osteomalacia (TIO), usually through fibroblast growth factor 23 (FGF-23) secretion. They arise in bone or soft tissue and present with non-specific symptoms, often leading to delayed diagnosis. This study evaluates tumor characteristics, the role of surgical therapy, and its impact on outcomes while highlighting key aspects of PMT management. Methods: A systematic review was conducted according to PRISMA guidelines, including 188 studies and 584 PMT cases, focusing on clinical presentation, treatment modalities, and outcomes. In addition, we retrospectively analyzed four patients treated at our institution. Results: The mean patient age was 49 ± 15 years, with a slight male predominance (56%). Tumors were evenly distributed between bone and soft tissue, most commonly affecting the lower extremities. Frequent symptoms included pain (90%) and pathological fractures (69%). Elevated FGF-23 levels were detected preoperatively in over 90% of cases. Complete remission was achieved in 66.2% of surgically treated patients compared to 29.4% of non-operatively managed patients (P < 0.001). Complete resection was associated with significantly higher remission rates (55.7 vs 6.6%, P = 0.001), particularly in bone-localized PMT. In our case series, all patients undergoing complete resection showed no evidence of disease and relief of TIO-associated symptoms. Conclusions: PMTs often lead to diagnostic delays due to non-specific symptoms. Complete surgical resection is the strongest predictor of favorable outcomes, especially for bone-localized tumors. An interdisciplinary approach is critical for early diagnosis, optimal treatment, and maximizing favorable clinical outcomes.