A Challenging Case of Tumor-Induced Osteomalacia: Pathophysiological and Clinical Implications.

We investigated the usefulness of fibroblast growth factor 23 (FGF23) intraoperative assay to monitor tumor resection in patients with oncogenic osteomalacia. A 33-year-old man with 5 years' history of lumbar and pelvis pain together with multiple vertebral fractures was admitted to our hospital. He was diagnosed with ankylosing spondylitis 1 year before. Laboratory investigation showed low tubular reabsorption of phosphate (0.41 mmol/L) despite chronic hypophosphatemia (0.39/L). Increased plasma values of FGF23 (673 pg/mL; n.v. < 95 pg/mL) were also observed. A full-body CT scan showed two suspicious areas in the head of the right femur and in the right tibia; however, the Octreoscan™ showed an increased uptake of the tracer only in the femur. We decided to remove first the head femur lesion and perform intraoperative FGF23 assay to confirm tumor resection; if this had been unsuccessful, we would have extended the operation to excise the second bone lesion. FGF23 basal values and 10, 60, and 225 min after excision of the femoral head were 423, 127, 56, and 30 pg/mL, respectively. The brisk fall of FGF23 values suggested that the head femur lesion was responsible for the syndrome. Histological examination revealed a mesenchymal highly vascular tumor. This is the first report showing the possibility of intraoperative FGF23 assay to monitor tumor resection in patients with tumor-induced osteomalacia.

Osteoid osteoma: MR-guided focused ultrasound for entirely noninvasive treatment.

PURPOSE: To determine the preliminary feasibility, safety, and clinical efficacy of magnetic resonance (MR)-guided focused ultrasound for the treatment of painful osteoid osteoma. MATERIALS AND METHODS: This prospective institutional review board-approved study involved six consecutive patients (five males and one female; mean age, 21 years) with a diagnosis of osteoid osteoma based on clinical and imaging findings. All patients underwent MR-guided focused ultrasound ablation after providing informed consent. Lesions located in the vertebral body were excluded. The number of sonications and the energy deposition were recorded. Treatment success was determined at 1, 3, and 6 months after treatment. A visual analog scale (VAS) score for pain was used to assess changes in symptoms. MR imaging features of osteoid osteoma (edema, hyperemia, and nidus vascularization) were considered at baseline and at imaging follow-up. RESULTS: Treatment was performed with a mean of 4 sonications ± 1.8 (standard deviation), with a mean energy deposition of 866 J ± 211. No treatment- or anesthesia-related complications occurred. The pre- and posttreatment mean VAS scores significantly differed (7.9 ± 1.4 and 0.0 ± 0.0, respectively). At imaging, the edema and hyperemia associated with osteoid osteoma gradually disappeared in all lesions. However, nidus vascularization still persisted after treatment in four of six patients. CONCLUSION: This limited series demonstrated that MR-guided focused ultrasound treatment of osteoid osteoma can be performed safely with a high rate of success and without apparent treatment-related morbidity.

Total hip replacement rate in a cohort of patients affected by symptomatic hip osteoarthritis following intra-articular sodium hyaluronate (MW 1,500-2,000 kDa) ORTOBRIX study.

Hip osteoarthritis is very common and costly. The European League Against Rheumatology Committee agenda asks for research to investigate treatments able to slow down the progression of hip osteoarthritis (OA), to delay joint replacement, and to determine the comparative effectiveness and cost-effectiveness of non-surgical and surgical treatment modalities as well as criteria relating to the indications for and timing of total hip replacement (THR). After publishing the results of a randomized controlled trial and a cohort study on the efficacy of Intra-articular sodium hyaluronate (MW 1,500-2,000 kDa) on symptomatic hip OA, we performed this retrospective study in patients suffering from hip OA treated with ultrasound-guided intra-articular injections of HyalOne (Hyalubrix 60 Italian brand name) involving a group of THR expert orthopedic surgeons to appraise whether or not considered eligible for THR and the frequency and timing of THR. Six orthopedists, not routinely performing hip intra-articular injections, each independently assessed whether 176 patients suffering from hip OA and treated with ultrasound-guided intra-articular injections of sodium hyaluronate (MW 1,500-2,000 kDa) were candidates for THR according to the clinical data (age, body mass index, Pain Visual Analog Scale, Lequesne Algofunctional Index, global patient assessment, global physician assessment, nonsteroidal anti-inflammatory drug intake, and hip X-ray) collected at the first intra-articular sodium hyaluronate injection visit and provided as anonymous electronic data. At 24 months, 159 out of 76 (90 %) patients did not undergo to THR. At 48 months, 82 % (N = 144) of the study population treated with intra-articular hyaluronic acid avoided THR. In the group of 93 patients considered candidates for THR (that is, in which 4, 5, or 6 orthopedic surgeons agreed that the patient was a suitable candidate for THR), only 17 had undergone THR, with survival results of 82 % at 24 months. At 48 months, this percentage reduced to 66 % in this group. In the other groups of patients (in which respectively 3, 2, 1 or no surgeons were in agreement that the patient was a candidate for THR) arthroplasty is not recorded. Sodium hyaluronate (MW 1,500-2,000 kDa) given by ultrasound-guided injection seems to delay THR in the real context of actual overall management of symptomatic hip OA patients. Although further studies are necessary to confirm these data and to identify outcome predictors, hip viscosupplementation should be considered as conservative treatment to perform before proposing patients for THR.

Increased expression of a set of genes enriched in oxygen binding function discloses a predisposition of breast cancer bone metastases to generate metastasis spread in multiple organs.

Bone is the preferential site of distant metastasis in breast carcinoma (BrCa). Patients with metastasis restricted to bone (BO) usually show a longer overall survival compared to patients who rapidly develop multiple metastases also involving liver and lung. Hence, molecular predisposition to generate bone and visceral metastases (BV) represents a clear indication of poor clinical outcome. We performed microarray analysis with two different chip platforms, Affymetrix and Agilent, on bone metastasis samples from BO and BV patients. The unsupervised hierarchical clustering of the resulting transcriptomes correlated with the clinical progression, segregating the BO from the BV profiles. Matching the twofold significantly regulated genes from Affymetrix and Agilent chips resulted in a 15-gene signature with 13 upregulated and two downregulated genes in BV versus BO bone metastasis samples. In order to validate the resulting signature, we isolated different MDA-MB-231 clonal subpopulations that metastasize only in the bone (MDA-BO) or in bone and visceral tissues (MDA-BV). Six of the signature genes were also significantly upregulated in MDA-BV compared to MDA-BO clones. A group of upregulated genes, including Hemoglobin B (HBB), were involved in oxygen metabolism, and in vitro functional analysis of HBB revealed that its expression in the MDA subpopulations was associated with a reduced production of hydrogen peroxide. Expression of HBB was detected in primary BrCa tissue but not in normal breast epithelial cells. Metastatic lymph nodes were frequently more positive for HBB compared to the corresponding primary tumors, whereas BO metastases had a lower expression than BV metastases, suggesting a positive correlation between HBB and ability of bone metastasis to rapidly spread to other organs. We propose that HBB, along with other genes involved in oxygen metabolism, confers a more aggressive metastatic phenotype in BrCa cells disseminated to bone.