Clinical management and postoperative follow up of 12 patients with tumor-induced osteomalacia / 中华内分泌代谢杂志

ABSTRACT

Objective To better understand the clinical management of tumor-induced osteomalacia (TIO) by analyzing the clinical features, diagnosis, treatment, postoperative biochemical changes, and clinical status in 12 cases of TIO. Methods Twelve cases of TIO hospitalized from 2004 to April 2010 were reviewed retrospectively. All cases were diagnosed based on their clinical manifestation, hypophosphatemia, and image study including technetium-99m octreotide scintigraphy (99mTc-Oct). Resuits There were 7 males and 5 females with mean age of (41.8±9.6) years (20 to 56 years). The course of disease was from 2 to 14 years ( median course 4.0 years). They all presented with bone pain, gait disturbance, muscle pain, and muscle weakness. Serum phosphate( Pi)levels were low in 12 cases with a range from 0.30 to 0.56 mmol/L. 99mTc-Oct was performed in 9 cases and it showed that the lesions were located in head of femur, fibula, retrocalcaneal area, foot, humerus,metacarpal, posterior chest wall or near nasal bone (apex partis petrosae ossis temporalis). Subcutaneous soft tissue mass was found in another 3 cases at loin, thigh, and foot by physical examination. The tumors were confirmed by CT, MRI or ultrasonography. Twelve patients underwent operation to remove the tumors and histopathology showed hemangioendothelioma or fibrous angioma (6 cases), giant cell tumor or fibroma of tendon sheath(4 cases), liposarcoma(1case), and phosphaturic mesenchymal tumor(1case). Serum Pi levels returned to normal in 10 patients after resection of tumor. During 2 to 64 months follow up, symptoms of bone pain and muscle weakness were improved obviously. Conclusions Patients with hypophosphatemic osteomalacia should be thoroughly investigated for TIO. 99mTc-Oct and other imaging examinations can effectively locate the tumors. Once the hidden tumor is found and excised, the patient will recover and enjoy normal life with normalized Pi concentrations and marked improvement of symptoms.