Severe osteomalacia with multiple insufficiency fractures secondary to intravenous iron therapy in a patient with Rendu-Osler-Weber syndrome.

SUMMARY: This case report describes a 65-year-old man with a Rendu-Osler-Weber syndrome with secondary chronic anaemia, who received multiple intravenous (IV) iron infusions and sustained diffuse bone pain secondary to multiple insufficiency fractures. Laboratory study confirmed fibroblast growth factor 23 (FGF-23)-mediated hypophosphatemia as the main cause of a severe osteomalacia induced by ferric carboxymaltose (FCM).After 3 months or oral phosphate replacement and switching to iron sucrose, serum phosphate levels were normalized and patient improved clinically. INTRODUCTION: Some drugs can induce asymptomatic hypophosphatemia, which if sustained, can lead to a severe osteomalacia with multiple skeletal fractures. This complication has also been described with IV iron therapy. METHODS: This case report describes a patient with Rendu-Osler-Weber syndrome with chronic iron deficiency anaemia, recurrently treated with FCM, who developed a severe osteomalacia with multiple skeletal fractures. RESULTS: Laboratory study showed hypophosphatemia, with high ALP and high FGF-23. Images studies confirmed bone mass loss and multiple insufficiency fractures. A Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) did not show hidden tumor, so a diagnosis of FCM-induced hypophosphatemic osteomalacia was performed. Phosphate replacement improved clinical symptoms of the patient. CONCLUSION: Intravenous iron therapy, mainly FCM form, can cause hypophosphatemia, and in some cases induce a severe osteomalacia with multiple fractures, so it seems advisable to monitor serum phosphate levels in high risk patients, as those who receive repeated dose.

18F-FDG PET/CT in breast cancer: Evidence-based recommendations in initial staging.

Current guidelines do not systematically recommend 18F-FDG PET/CT for breast cancer staging; and the recommendations and level of evidence supporting its use in different groups of patients vary among guidelines. This review summarizes the evidence about the role of 18F-FDG PET/CT in breast cancer staging and the therapeutic and prognostic impact accumulated in the last decade. Other related aspects, such as the association of metabolic information with biology and prognosis are considered and evidence-based recommendations for the use of 18F-FDG PET/CT in breast cancer staging are offered. We systematically searched MEDLINE for articles reporting studies with at least 30 patients related to clinical questions following the Problem/Population, Intervention, Comparison, and Outcome framework. We critically reviewed the selected articles and elaborated evidence tables structuring the summarized information into methodology, results, and limitations. The level of evidence and the grades of recommendation for the use of 18F-FDG PET/CT in different contexts are summarized. Level III evidence supports the use of 18F-FDG PET/CT for initial staging in patients with recently diagnosed breast cancer; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a weak recommendation in this population. In patients with locally advanced breast cancer, level II evidence supports the use of 18F-FDG PET/CT for initial staging; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a strong recommendation in this population. In patients with recently diagnosed breast cancer, the metabolic information from baseline 18F-FDG PET/CT is associated with tumor biology and has prognostic implications, supported by level II evidence. In conclusion, 18F-FDG PET/CT is not recommended for staging all patients with early breast cancer, although evidence of improved regional and systemic staging supports its use in locally advanced breast cancer. Baseline tumor glycolytic activity is associated with tumor biology and prognosis.

18F-fluorodeoxyglucose positron emission tomography in the diagnosis of malignancy in patients with paraneoplastic neurological syndrome: a systematic review and meta-analysis.

PURPOSE: The detection of occult cancer in patients suspected of having a paraneoplastic neurological syndrome (PNS) poses a diagnostic challenge. The aim of our study was to perform a systematic review and meta-analysis to assess the diagnostic performance of FDG PET for the detection of occult malignant disease responsible for PNS. METHODS: A systematic review of the literature (MEDLINE, EMBASE, Cochrane, and DARE) was undertaken to identify studies published in any language. The search strategy was structured after addressing clinical questions regarding the validity or usefulness of the test, following the PICO framework. Inclusion criteria were studies involving patients with PNS in whom FDG PET was performed to detect malignancy, and which reported sufficient primary data to allow calculation of diagnostic accuracy parameters. When possible, a meta-analysis was performed to calculate the joint sensitivity, specificity, and detection rate for malignancy (with 95% confidence intervals [CIs]), as well as a subgroup analysis based on patient characteristics (antibodies, syndrome). RESULTS: The comprehensive literature search revealed 700 references. Sixteen studies met the inclusion criteria and were ultimately selected. Most of the studies were retrospective (12/16). For the quality assessment, the QUADAS-2 tool was applied to assess the risk of bias. Across 16 studies (793 patients), the joint sensitivity, specificity, and detection rate for malignancy with FDG PET were 0.87 (95% CI: 0.80-0.93), 0.86 (95% CI: 0.83-0.89), and 14.9% (95% CI: 11.5-18.7), respectively. The area under the curve (AUC) of the summary ROC curve was 0.917. Homogeneity of results was observed for sensitivity but not for specificity. Some of the individual studies showed large 95% CIs as a result of small sample size. CONCLUSIONS: The results of our meta-analysis reveal high diagnostic performance of FDG PET in the detection of malignancy responsible for PNS, not affected by the presence of onconeural antibodies or clinical characteristics.