A Rare Association Between Osteomalacia, Phosphaturic Mesenchymal Tumor, and Ovarian Cancer: A Case Report and Literature Review.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by hypophosphatemia, bone mineralization disorders with increased risk of fragility fractures, muscle pain, and progressive weakness. TIO has been associated with increased production of the phosphaturic hormone Fibroblast Growth Factor 23 (FGF23) usually by mesenchymal tumors of soft tissue or bone (Phosphaturic Mesenchymal Tumors-PMTs). In rare cases TIO may be observed in association with other malignancies. We report the case of a 66-year-old woman with an occasional diagnosis of both a PMT and an ovarian cancer during the evaluation of TIO. We also systematically review the literature to discover possible correlations between osteomalacia, FGF23 production, and ovarian cancer. Four studies were eligible for the analysis. Two case reports described an association between TIO development and ovarian cancer, whereas the two case-control studies hypothesized a possible correlation between FGF/FGF receptor axis and cancer development. Although it does not provide conclusive evidence regarding the association between TIO and ovarian cancer, this case report highlights the possibility that in the diagnostic workup of suspected TIO, both FGF23-secreting tumors distinct from PMT and tumors unrelated to the clinical presentation of TIO could be identified. This information is important for guiding successful tumor staging and determining the necessity for surgical intervention and/or eventual adjuvant therapy.

Rare renal proximal tubular dysfunctions in primary biliary cholangitis.

INTRODUCTION: Renal involvement of primary biliary cholangitis (PBC) usually presents as distal renal tubular acidosis. Proximal tubular (PT) dysfunctions in PBC were rarely reported with unclear clinicopathological characteristics and renal prognosis. METHODS: We identified 11 cases of PBC with PT dysfunctions (PBC-PT). Their medical document, kidney pathology, and follow-up data were retrospectively reviewed and analyzed. RESULTS: The 11 PBC-PT patients were mainly middle-aged (57.8 ± 5.2 years) females (81.8%). Most of them were asymptomatic PBC (7, 63.6%) with a high prevalence of elevated serum immunoglobulin M (IgM, 81.8%) and G (IgG, 54.5%) levels. In the kidney, they had a mean estimated glomerular filtration rate (eGFR) level of 46.54 ± 23.03 ml/min/1.73m2, and 81.8% of them had eGFR below 60 ml/min/1.73m2. They showed different degrees of PT dysfunctions, including hyperuricosuria, hypouricemia, normoglycemic glycosuria, generalized aminoaciduria, hyperphosphaturia, and hypophosphatemia. Their kidney pathology showed tubulointerstitial nephritis with lymphoplasmacytic infiltrates, brush border defects, and proximal tubulitis. After glucocorticoids treatment, the PT dysfunctions manifesting as hypophosphatemia, hypouricemia, and renal glycosuria all recovered, and the eGFR levels were improved from 43.24 ± 19.60 ml/min/1.73m2 to 55.02 ± 21.14 ml/min/1.73m2 (p = 0.028), accompanied by significant improvements of serum IgM levels (from 5.97 ± 4.55 g/L to 2.09 ± 1.48 g/L, p = 0.019). CONCLUSIONS: The PT dysfunctions were rare in PBC patients, and glucocorticoids treatment could benefit the improvements of eGFR and tubular functions.

Cost-utility analysis of ferric derisomaltose versus ferric carboxymaltose in patients with inflammatory bowel disease and iron deficiency anemia in England.

AIMS: Anemia is the most common extraintestinal complication of inflammatory bowel disease (IBD), with approximately half of cases caused by iron deficiency (ID). Intravenous iron is the preferred ID anemia (IDA) treatment where oral iron is contraindicated, ineffective or not tolerated, or where ID correction is urgent. The objective was to evaluate the cost-utility of ferric derisomaltose (FDI) versus ferric carboxymaltose (FCM) in patients with IBD and IDA in England, in whom IV iron treatment is preferred. MATERIALS AND METHODS: A patient-level simulation model was developed, capturing quality of life (QoL) differences based on SF-36v2 data from the PHOSPHARE-IBD randomized controlled trial, monitoring and incidence of post-infusion hypophosphatemia, and number of iron infusions required. Analyses were conducted over a five-year time horizon from the Department of Health and Social Care (DHSC) perspective, with healthcare provider and societal perspectives adopted in separate analyses. Future costs and effects were discounted at 3.5% per annum and one-way and probabilistic sensitivity analyses were performed. RESULTS: FDI increased quality-adjusted life expectancy by 0.075 QALYs versus FCM from 2.57 QALYs to 2.65 QALYs per patient. Patients receiving FDI required 1.63 fewer iron infusions over the five-year time horizon, driving infusion-related cost savings of GBP 496 per patient (GBP 2,188 versus GBP 1,692) from the DHSC perspective. Costs of monitoring and treating hypophosphatemia after FCM were GBP 226, yielding total savings of GBP 722 per patient (GBP 2,414 versus GBP 1,692) over the five-year time horizon. FDI also led to reduced costs versus FCM in the societal and provider analyses and was therefore the dominant intervention across all three perspectives. LIMITATIONS: The analysis did not capture patient adherence, hypophosphatemic osteomalacia, or fractures. CONCLUSIONS: Results showed that FDI improved patient QoL and reduced direct healthcare expenditure versus FCM in patients with IBD and IDA in England.

Ferric derisomaltose (FDI) is an intravenous iron approved for the treatment of clinically diagnosed iron deficiency in the United Kingdom (UK), and can be an important therapeutic option for patients with inflammatory bowel disease (IBD), who require regular and rapid iron replenishment. Ferric carboxymaltose (FCM) is the sole alternative intravenous iron formulation available in the UK, but is associated with reduced blood phosphate levels, potentially causing fatigue and weakening of the bones. We conducted an economic analysis to weigh the costs and clinical outcomes associated with FDI and FCM in the UK, for patients with IBD and iron deficiency anemia (IDA). The main clinical difference we investigated was reduced blood phosphate levels, which occurred more often after FCM than FDI. We also incorporated recent quality of life data from a clinical study, and calculated the number of infusions (and associated costs) of each iron formulation, that patients would require over five years. Clinical data were obtained from published medical literature, while cost data came from UK sources including the 2022/2023 National Tariff Payment System and the British National Formulary. Our model showed that FDI was associated with quality of life improvements, fewer overall infusions per treatment course, and reduced costs compared to FCM, from the English Department of Health and Social Care perspective, the societal perspective, and the perspective of individual healthcare providers (namely NHS Trusts) within NHS England. FDI is therefore likely to represent the best value intravenous iron for the treatment of IDA with IBD in the UK.

Tumor-induced osteomalacia: a case report / Osteomalácia induzida por tumor: relato de caso

Tumor-induced osteomalacia (TIO) is a rare paraneoplasic syndrome with overproduction of fibroblast growth factor 23 as a phosphaturic agent, leading to chronic hyperphosphaturia and hypophosphatemia, associated with inappropriately normal or low levels of 1,25-dihydroxyvitamin D. Diagnosis of this disease is often challenging. The following case report described a middle-aged man with symptoms of bone pain and severe muscle weakness, who was found to have TIO. The tumor responsible for the symptoms was localized on his thigh and its resection resulted in normalization of blood chemistry and complaints. Subsequent microscopic examination revealed a phosphaturic mesenchymal tumor, mixed connective tissue type. The authors reinforce the importance of recognition of this disease, as severe disability and even death can be avoided with the surgical removal of the causative tumor.

Osteomalácia induzida por tumor (OIT) é uma síndrome paraneoplásica rara, causada por hiperprodução do agente fosfatúrico, levando a hipofosfatemia e hiperfosfatúria crônicas, associadas a níveis reduzidos ou inapropriadamente normais de 1,25-dihidroxivitamina D. O diagnóstico dessa doença é, geralmente, desafiador. O relato de caso aqui apresentado descreveu um homem de meia-idade, com quadro inicial de dor óssea, fraqueza muscular extrema e hipofosfatemia, com diagnóstico tardio de OIT. O tumor responsável pelos sintomas foi localizado em membro inferior, e sua exérese resultou em normalização das alterações bioquímicas e dos sintomas. O exame microscópico da lesão revelou tumor mesenquimal fosfatúrico, tecido conectivo misto. Os autores reforçam a importância do reconhecimento dessa entidade, uma vez que a remoção do tumor responsável pelos sintomas pode evitar sérias complicações ou mesmo a morte.

Hiperparatireoidismo associado à osteomalacia hipofosfatêmica do adulto: relato de caso e revisão da literatura / Hyperparathyroidism associated with hypophosphatemic osteomalacia: case report and review of the literature

A osteomalacia hipofosfatêmica é uma doença rara caracterizada por hipofosfatemia, níveis elevados de fosfatase alcalina e diminuição da densidade óssea. O tratamento é realizado com suplementação oral com fosfato e vitamina D e, nos casos de osteomalacia oncogênica, com a ressecção do tumor. Relatamos o caso de uma paciente que apresentou quadro de osteomalácia hipofosfatêmica de causa indeterminada. Apesar de extensivamente procurado, nenhum tumor produtor de substância hipofosfatêmica foi localizado. A paciente foi tratada como suplementação de fosfato e vitamina D por longo período, evoluindo com quadro de hiperparatireoidismo terciário. A retirada de três paratireóides não normalizou os níveis de PTH e a paciente recusou-se a continuar a investigação e o tratamento. Após dez anos de tratamento irregular, foi internada por insuficiência respiratória causada por colabamento do arcabouço costal e múltiplas fraturas, evoluindo para o óbito. Os autores discutem a relação entre osteomalácia e hiperparatireoidismo e o curso agressivo da doença.

Papel da histomorfometria óssea no diagnóstico diferencial da osteomalacia / Role of bone histomorphometry in the differential diagnosis of osteomalacia

A osteomalacia é uma doença ósteo-metabólica em que há deficiente mineralização do osso, e é definida pela histomorfometria óssea por apre-sentar espessura do rebordo osteóide (O.Th) maior do que 15µm, e inter-valo de tempo para mineralização (MLT) maior do que 100 dias. As princi-pais etiologias de osteomalacia são a deficiência de ação da vitamina D e a hipofosfatemia. Neste trabalho, 14 pacientes com osteomalacia diag-nosticados clínica e laboratorialmente foram divididos em dois grupos: 6 pacientes com deficiente ação de vitamina D e 8 hipofosfatêmicos. Todos os pacientes apresentaram ao exame histomorfométrico aumento do O.Th e do MLT compatível com o diagnóstico de osteomalacia. A superfície de reabsorção óssea estava aumentada no grupo com defi-ciência de ação da vitamina D. Em seis pacientes hipofosfatêmicos, a superfície de reabsorção óssea estava ausente, em um paciente dentro da normalidade mas em um paciente encontrava se aumentada. Con-clusão: a histomorfometria dinâmica óssea através da análise dos parâmetros de formação confirmam o diagnóstico de osteomalacia, enquanto que os parâmetros de reabsorção permitem uma orientação etiológica.

Sídrome de Realimentación

Bajo el término de síndrome de realimentación se agrupan una serie de trastornos metabólicos como hipofosfatemia severa entre otros, observados en pacientes desnutridos sometidos a diferentes terapias de repleción nutricional, bien por vía parenteral o enteral. Se presentan dos casos con manifestaciones similares luego de iniciar la terapia de realimentación, uno parenteral y otro enteral, que mostraton cifras bajas de fósforo con trastornos de la conciencia y neuromusculares que cedieron con la suplementación de este anión. El propósito de la actual revisión es ampliar la definición del síndrome y clarificar los otros trastornos, además de la hipofosfatemia encontrados con la repleción nutricional, así como tipificar los diferentes pacientes en quienes es posible que aparezca esta complicación y por último hacer recomendaciones para su reconocimiento y más importante aún; para su prevención.

Osteomalacia hipofosfémica adquirida post-trasplante renal: una causa de osteoporosis grave / Hypophosphatemic osteomalacia adquiared post renal transplantation: a cause of severe osteoporosis

Renal osteodystrophy improves after renal transplantation but, after the procedure, other forms of bone disease emerge. We report a male patient that received a renal allograft four years before, who consulted for low back pain secondary to multiple vertebral compression fractures. The patient had good renal function, a parathormone independent hyperphosphaturia, normal 25-OH cholecalciferol, increased urinary hydroxyproline, decreased osteocalcin, reduced bone density and a bone biopsy revealing osteomalacia. The diagnosis of hypophosphemic osteomalacia was reached and treatment with phosphates and ergocalciferol was started but, despite this, the patient suffered a new fracture 2 years later. Two mechanisms can produce hypophosphatemia after a renal transplantation: a parathormone excess due to the previous renal failure, that disappears during the first year after the transplantation or a derangement in renal phosphate transport that can be due to a generalized proximal tubule solute transport derangement (Fanconi syndrome), parathormone hypersensitivity or to an idiopathic hyperphosphaturia. Despite a good treatment, bone mass is not recovered and there is a high fracture risk. Mineral metabolism must be closely monitored after a renal allograft and its alterations must be quickly treated