RESUMO
Tumor-induced osteomalacia (TIO) is a rare disease that behaves benignly. Very few reports about the features of the responsible tumors according to anatomical locations have been presented.In this retrospective study of 53 patients with TIO-associated tumors in the foot/ankle, tibia and femur, we compared preoperative, postoperative, and follow-up courses, including alkaline phosphatase, phosphorus, and fibroblast growth factor 23, to compare the characteristics of TIO-associated tumors in these 3 locations (level of evidence: therapeutic level III).Patients in the foot/ankle group had longer disease courses and therefore a significantly higher complication rate (Pâ<â.001). All TIO-associated tumors in the foot/ankle group involved soft tissue (Pâ=â.021), whereas most lesions in the tibia group involved bone, and therefore had much higher concentrations of alkaline phosphatase (Pâ=â.020). Additionally, serum phosphorus took much longer to normalize after surgery in the foot/ankle group than that in the other 2 groups (Pâ=â.004). Consequently, symptom remission was much better in the tibia and femur groups (Pâ=â.008). Moreover, the Ki 67 index in TIO-associated tumors was significantly higher in the foot/ankle group (Pâ<â.001) and the recurrence rate in this group was markedly higher (Pâ=â.002).The TIO-associated tumors in the foot/ankle are characteristically of occult onset, more soft-tissue involvement, and more readily recurrence. More knowledge and examinations are necessary to enable early diagnosis, radical treatments, and minimize recurrence. New therapies are welcomed and needed.