Tumor-induced osteomalacia: An overview.

Tumor-induced osteomalacia (TIO) is rare paraneoplastic syndrome of hypophosphatemic osteomalacia, caused by phosphaturic factors secreted by small mesenchymal origin tumors with distinct pathological features, called 'phosphaturic mesenchymal tumors'. FGF23 is the most well-characterized of the phosphaturic factors. Tumors are often small and located anywhere in the body from head to toe, which makes the localisation challenging. Functional imaging by somatostatin receptor-based PET imaging is the first line investigation, which should be followed with CT or MRI based anatomical imaging. Once localised, complete surgical excision is the treatment of choice, which brings dramatic resolution of symptoms. Medical management in the form of phosphate and active vitamin D supplements is given as a bridge to surgical management or in inoperable/non-localised patients. This review provides an overview of the epidemiology, pathophysiology, pathology, clinical features, diagnosis, and treatment of TIO, including the recent advances and directions for future research in this field.

Diagnosis and management of tumor-induced osteomalacia: a single center experience.

PURPOSE: The aim of this study is to review the clinical and laboratory characteristics, diagnostic and treatment modalities of tumor-induced osteomalacia (TIO) cases managed in a single center. MATERIAL METHODS: Demographic and clinical features, biochemical findings, diagnostic procedures, treatment modalities, and outcomes of nine patients who had the diagnosis of TIO were reviewed retrospectively. RESULTS: Mean age of the study group (F/M: 4/5) was 45.8 ± 10.8 years, and mean time from the onset of symptoms to diagnosis was 4.7 ± 2.8 years. The clinical manifestations were muscle weakness and difficulty in walking (8/9), hip pain (3/9), multiple fractures (2/9), stress fracture (2/9). Mean plasma phosphorus concentration was 1.28 ± 0.4 mg/dl at presentation. We performed radionuclide imaging modalities (18F-FDG PET/CT, Ga68-DOTATATE PET/CT, octreotide scintigraphy) in seven of nine patients, and tumor was detected in all. Lower extremity (n = 6; %67), head region (n = 2; %22) and thorax (n = 1; %11) were the tumor locations of our cases. Eight patients underwent surgery and remission was achieved postoperatively in all of the operated patients and plasma phosphorus level normalized in 4 ± 2 days. Pathological examination revealed mesenchymal tumors with different subtypes. Recurrence occurred in three patients at 13 ± 10.5 months after the first surgery. Two patients were reoperated and radiotherapy was also performed in one of them. CONCLUSION: Hypophosphatemia necessitates careful evaluation for the etiology. TIO is one of the important causes of adult-onset hypophosphatemic osteomalacia. Diagnosis of TIO is essential because the laboratory and clinical findings resolve after appropriate treatment.

Tumor-induced osteomalacia combined with increased bone resorption postoperatively: A case report.

RATIONALE: Rare tumor-induced osteomalacia (TIO) usually resulted in bone pain, fragility fractures and muscle weakness in clinical, which is caused by the reduced phosphate reabsorption, thus impaired mineralization of the bone matrix and free energy transfer. The specific problems in postsurgical patients are obscure although surgical removal of the tumor is the only definitive treatment. Here, we documented a female TIO patient who suffered more severe bone pain and muscle spasms post-operation. Further, we presented and discussed our explanation for the unexpected symptoms. PATIENT CONCERNS: The main symptoms were whole-body pain and muscle weakness. The patient also presented with osteoporosis and multiple fractures. DIAGNOSIS: Elevated serum fibroblast growth factor 23 (FGF23) level and hypophosphatemia indicated the diagnosis of TIO. Positron emission tomography (PET)/computed tomography (CT) with 68 Ga-DOTATATE located the tumor in the dorsolateral part of the left foot. Histopathological examinations confirmed the diagnosis. INTERVENTIONS: The tumor was surgically removed immediately after the diagnosis of TIO and localization of the tumor. Postoperatively, calcium carbonate supplement treatment was continued. OUTCOMES: Two days after surgery, the serum FGF23 level was decreased to the normal range. Five days after surgery, N-terminal propeptide of type I procollagen and ß-CrossLaps (ß-CTx) had a remarkable increase. A month after surgery, the patient N-terminal propeptide of type I procollagen and ß-CTx levels were decreased obviously, and serum FGF23, phosphate and 24h urinary phosphate were in the normal range. LESSONS: We report a female patient who presented with osteoporosis and fractures. She was found with an elevation of FGF23 and diagnosis with TIO after PET/CT scanning. After surgically removing the tumor, the patient experienced more severe bone pain and muscle spasms. Active bone remodeling might be the reason for the symptoms. Further study will reveal the specific mechanism for this abnormal bone metabolism.

[FGF23 tumor induced osteomalacia].

Tumor induced osteomalacia is a rare acquired disease. The cause is a mesenchymal tumor secreting fibroblast growth factor 23 (FGF23). An excessive amount of FGF 23 disrupts the metabolism of phosphorus and vitamin D, which leads to severe paraneoplastic syndrome, manifested in the form of multiple fractures, severe pain in the bones and generalized myopathy. With oncogenic osteomalacia, a complete cure is possible with radical resection of the tumor. Unfortunately, localization, small size of formations and rare frequency of occurrence lead to the fact that the disease remains unrecognized for a long time and leads to severe, disabling consequences. A step-by-step approach to diagnosis improves treatment outcomes. First, a thorough anamnesis is collected, then functional visualization is performed and the diagnosis is confirmed by anatomical visualization of the tumor. After that, the method of choice is a surgical treatment. If resection is not possible, then conservative therapy with active metabolites of vitamin D and phosphorus salts is indicated. New therapeutic approaches, such as the antibody to FGF23 or the pan-inhibitor of receptors to FGF, are actively developing. This article provides an overview of modern approaches to the diagnosis and treatment of this disease.

Occult phosphaturic mesenchymal tumour of femur cortex causing oncogenic osteomalacia - diagnostic challenges and clinical outcomes.

BACKGROUND: Tumor induced osteomalacia (TIO) are extremely rare paraneoplastic syndrome with less than 300 reported cases. This report highlights the pitfalls and challenges in diagnosing and localizing TIO in patients with refractory and resistant osteomalacia. PATIENT AND METHODS: 41- year gentleman with 4-year history of musculoskeletal weakness and pathologic fractures presented in wheelchair bound incapacitated state of 1-year duration. Investigations were significant for severe hypophosphatemia, severe phosphaturia, normal serum calcium, reduced 1,25-dihydroxy vitamin-D, elevated ALP, elevated intact parathyroid hormone (iPTH), and pseudo-fractures involving pelvis and bilateral femur. Whole body MRI and 99mTc methylene diphosphonate bone-scan were also normal. Whole body FDG-PET scan involving all 4 limbs revealed a small FDG avid lesion at lateral border of lower end of left femur (SUV max 3.9), which was well characterized on 3-dimensional CT reconstruction. Plasma C-terminal fibroblast growth factor (FGF)-23 was 698 RU/ mL (normal < 150 RU/ml). Wide surgical excision of the tumor was done. Histopathology confirmed mesenchymal tumor of mixed connective tissue variant. Serum phosphorous normalized post-surgery day-1. High dose oral calcium and vitamin-D was continued. FGF-23 normalized post surgery (73RU/ml). Physical strength improved significantly and now he is able to walk independently. CONCLUSION: TIO is frequently confused with normocalcemic hyperparathyroidism and vitamin-D resistant rickets/osteomalacia, which increases patient morbidity. Imaging for tumor localization should involve whole body from head to tip of digits, cause these tumors are notoriously small and frequently involve digits of hands and legs. Complete surgical removal of the localized tumor is key to good clinical outcomes.

Diagnostic patterns and delays in autoimmune blistering diseases of the mouth: A cross-sectional study.

OBJECTIVES: To describe the natural history and factors influencing diagnostic delays among patients with autoimmune blistering diseases of the mouth. MATERIALS AND METHODS: In this cross-sectional study, 27 newly diagnosed patients were interviewed, and professional and patient delays were calculated. Disease extent and severity scores were determined using Saraswat scoring system. RESULTS: Twenty-seven patients were interviewed and examined. Patient delay was significantly longer in patients who had desquamative gingivitis as initial presentation, in those who tried to use home remedies and over the counter medications, and in patients with less severe disease. Most patients (n = 21 [77.7%]) made more than one consultation, and the mean time needed to reach a definitive diagnosis (i.e. professional delay) was 83.2 ± 21.4 days (range from 21 to 130 days). Professional delay was significantly correlated with the number of previous consultations (r = .78) and was significantly longer in patients who had desquamative gingivitis as initial presentation. CONCLUSION: Diagnosis of oral blistering diseases is often delayed. Diagnostic delay is more common in patients presenting with desquamative gingivitis and those with less severe disease. Improving patients and healthcare professionals' awareness about oral blistering diseases might help reduce diagnostic delay.

Tumor-induced Osteomalacia in a 3-Year-Old With Unresectable Central Giant Cell Lesions.

Tumor-induced osteomalacia (TIO) is a rare cause of hypophosphatemia involving overproduction of fibroblast growth factor 23. TIO has been described largely in adults with small mesenchymal tumors. We report a case of TIO in a child who presented with knee pain and radiographic findings concerning for rickets, and was found to have maxillomandibular giant cell lesions. The patient was treated with oral phosphorus and calcitriol, surgical debulking, and intralesional corticosteroids, which resulted in tumor regression and normalization of serum fibroblast growth factor 23 and phosphorus. This case illustrates the occurrence of this rare paraneoplastic syndrome in children and adds to our knowledge about clinical manifestations and pathologic findings associated with pediatric TIO.

Life-Threatening Hypercalcemia Revealing Diffuse and Isolated Acute Sarcoid-Like Myositis: A New Entity? (A Case-Series).

Up to 50% patients with sarcoidosis display extra-pulmonary disease. However, initial and isolated (ie, without lung disease) acute muscular involvement associated with pseudo-malignant hypercalcemia is very uncommon. We report on 3 cases of life-threatening hypercalcemia revealing florid and isolated acute sarcoid-like myositis.All patients complained of fatigue, progressive general muscle weakness, and weight loss. Laboratory tests showed a severe life-threatening hypercalcemia (>3.4 mmol/L). Hypercalcemia was associated with increased serum level of 1,25-(OH)2 vitamin D and complicated with acute renal failure. One patient displayed acute pancreatitis due to hypercalcemia.In all cases, PET-scan, performed for malignancy screening, incidentally revealed an intense, diffuse, and isolated muscular fluorodeoxyglucose (FDG) uptake consistent with diffuse non-necrotizing giant cells granulomatous myositis demonstrated by muscle biopsy. Of note, creatine phosphokinase blood level was normal in all cases. No patients displayed the usual thoracic features of sarcoidosis.All patients were treated with high dose steroids and achieved rapid, complete, and sustained remission. A review of English and French publications in Medline revealed 5 similar published cases.Steroid-sensitive acute sarcoid-like myositis causing high calcitriol levels and life-threatening hypercalcemia should be recognized as a separate entity.

Rheumatologic Skin Disease.

In common rheumatologic diseases skin findings are an important diagnostic clue for astute clinicians. Skin manifestations can help identify systemic disease or may require therapy uniquely targeted at the cutaneous problem. This article discusses 3 common rheumatologic conditions seen in adults by dermatologists: cutaneous lupus, dermatomyositis, and morphea. The focus is on the cutaneous findings and clinical presentation. Some approaches to treatment are explored. Clues to help identify systemic disease are also highlighted.

Locally aggressive and multifocal phosphaturic mesenchymal tumors: two unusual cases of tumor-induced osteomalacia.

Tumor-induced osteomalacia (TIO) has long been recognized as a clinical paraneoplastic syndrome. The identification of a unique histopathologic entity, the phosphaturic mesenchymal tumor (PMT), as a distinct etiology for TIO has been a more recent discovery. The majority of published cases describe a solitary, non-aggressive appearing soft tissue or osseous lesions in patients with osteomalacia; aggressive appearing or multifocal lesions appear to be exceedingly rare. These tumors characteristically secrete fibroblast growth factor 23 (FGF23). Elevated serum levels of FGF23 result in phosphate wasting and osteomalacia. In the majority of cases, laboratory abnormalities and clinical signs and symptoms of osteomalacia precede identification of the causative lesion by years. Following diagnosis, complete resection with wide margins to prevent local recurrence is most often curative. Imaging characteristics of PMT are diverse and remain incompletely defined, as the majority of previous publications are outside of the radiologic literature. We present multiple imaging modalities in two cases of patients with debilitating osteomalacia and unusual appearing PMTs: one with a locally aggressive lesion leading to pathologic fracture, the second presenting with exceedingly rare multifocal PMT.

Tumor-Induced Osteomalacia: an Up-to-Date Review.

Tumor-induced osteomalacia (TIO) is a paraneoplastic syndrome resulting in renal phosphate wasting and decreased bone mineralization. TIO is usually induced by small, slowly growing tumors of mesenchymal origin (phosphaturic mesenchymal tumor mixed connective tissue variant [PMTMCT]). Nonspecific symptoms including fatigue, bone pain, and musculoskeletal weakness make the diagnosis elusive and often lead to a delay in treatment. The prognosis of TIO is excellent following complete resection of the neoplasm, which leads to the rapid and complete reversal of all symptoms. If the tumor cannot be detected, treatment relies on supplementation with phosphate and active vitamin D compounds. Subsequent radiotherapy in case of incompletely resected tumors or definitive radiotherapy in unresectable tumors is an important treatment option to avoid recurrence or metastasis even though this occurs rarely. Due to the risk of recurrence or late metastases, long-term monitoring is required even in TIO patients diagnosed with a benign tumor.

Denosumab in hypercalcemia of malignancy: a case series.

BACKGROUND: Denosumab is a nuclear factor-kappa ligand monoclonal antibody whose FDA-approved indications include treatment of osteoporosis, bone loss with certain anticancer hormonal agents, and prevention of skeletal-related events in patients with bone metastases from solid tumors. In clinical trials, the incidence of severe hypocalcemia has been reported as 3.1-10.8%. To date, case reports and two clinical trials have reported the use of denosumab in the management of hypercalcemia of malignancy. No reports of denosumab-induced hypocalcemia have been reported for the hypercalcemia of malignancy population. METHODS: We performed a retrospective chart review of all patients who received denosumab for hypercalcemia of malignancy to describe the effects of denosumab on calcium levels at our institution. RESULTS: Seven patients received doses of denosumab for hypercalcemia of malignancy. The most common tumor types were breast cancer (n = 3) and hematologic malignancies (n = 2). All patients had bone involvement. Two patients received single doses of 60 mg. The other five patients received 120 mg. The mean corrected calcium levels were 13.7 mg/dL and 12.24 mg/dL for the days of admission and denosumab administration, respectively (p = 0.1889). The mean corrected calcium level for the last known value was 9.92 mg/dL, while in house (p = 0.0016). Supportive care prior to denosumab included hydration (n = 7), bisphosphonates (n = 6), and calcitonin (n = 5). One patient had a calcium level of 6.6 mg/dL on day 4 after denosumab, requiring calcium supplementation and telemetry. Of the seven patients treated with denosumab for hypercalcemia of malignancy at our institution, six patients were discharged alive. Of these, one patient died two days after discharge. Last-known follow-up was a median of 26 days, range, 3-195, for all patients. CONCLUSIONS: Denosumab helped decrease calcium in patients with hypercalcemia of malignancy. However, symptomatic hypocalcemia may result from denosumab in hypercalcemia of malignancy.

[Metabolic bone disease osteomalacia]. / Metabolische Knochenkrankheit Osteomalazie.

Osteomalacia is a rare disorder of bone metabolism leading to reduced bone mineralization. Underlying vitamin D deficiency and a disturbed phosphate metabolism (so-called hypophosphatemic osteomalacia) can cause the disease. Leading symptoms are dull localized or generalized bone pain, muscle weakness and cramps as well as increased incidence of falls. Rheumatic diseases, such as polymyalgia rheumatica, rheumatoid arthritis, myositis and fibromyalgia must be considered in the differential diagnosis. Alkaline phosphatase (AP) is typically elevated in osteomalacia while serum phosphate and/or 25-OH vitamin D3 levels are reduced. The diagnosis of osteomalacia can be confirmed by an iliac crest bone biopsy. Histological correlate is reduced or deficient mineralization of the newly synthesized extracellular matrix. Treatment strategies comprise supplementation of vitamin D and calcium and for patients with intestinal malabsorption syndromes vitamin D and calcium are also given parenterally. In renal phosphate wasting syndromes substitution of phosphate is the treatment of choice, except for tumor-induced osteomalacia when removal of the tumor leads to a cure in most cases.

Identifying potential clinical syndromes of hepatocellular carcinoma using PSO-based hierarchical feature selection algorithm.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Clinical symptoms attributable to HCC are usually absent, thus often miss the best therapeutic opportunities. Traditional Chinese Medicine (TCM) plays an active role in diagnosis and treatment of HCC. In this paper, we proposed a particle swarm optimization-based hierarchical feature selection (PSOHFS) model to infer potential syndromes for diagnosis of HCC. Firstly, the hierarchical feature representation is developed by a three-layer tree. The clinical symptoms and positive score of patient are leaf nodes and root in the tree, respectively, while each syndrome feature on the middle layer is extracted from a group of symptoms. Secondly, an improved PSO-based algorithm is applied in a new reduced feature space to search an optimal syndrome subset. Based on the result of feature selection, the causal relationships of symptoms and syndromes are inferred via Bayesian networks. In our experiment, 147 symptoms were aggregated into 27 groups and 27 syndrome features were extracted. The proposed approach discovered 24 syndromes which obviously improved the diagnosis accuracy. Finally, the Bayesian approach was applied to represent the causal relationships both at symptom and syndrome levels. The results show that our computational model can facilitate the clinical diagnosis of HCC.

Phosphaturic mesenchymal tumors show positive staining for somatostatin receptor 2A (SSTR2A).

Tumor-induced osteomalacia (TIO) is a paraneoplastic syndrome associated with tumors that secrete phosphaturic hormones, most notably fibroblast growth factor 23 (FGF23). The majority of tumors associated with this syndrome show stereotypical histological features and are now known as phosphaturic mesenchymal tumors (PMTs). We postulated that immunohistochemistry for somatostatin receptor 2A (SSTR2A) could be used to definitively identify PMTs or other tumors that cause TIO. Immunohistochemistry for FGF23 and SSTR2A was performed on 15 tumors from 14 patients with a definite diagnosis of TIO. All showed positive staining for both markers. While FGF23 staining was quite focal in some tumors, SSTR2A showed diffuse strong expression. In 40 control tumors not known to be associated with the clinical or biochemical features of TIO, FGF23 expression was found in 2 cases (one aneurysmal bone cyst and one osteosarcoma). SSTR2A expression was found in 9 control tumors (4 synovial sarcomas, 2 hemangiomas, 2 aneurysmal bone cysts and one osteosarcoma). Only one tumor (an aneurysmal bone cyst) showed positive staining for both FGF23 and SSTR2A. SSTR2A also commonly stained neoplastic and non-neoplastic endothelial cells. We conclude that neither FGF23 nor SSTR2A expression are specific for the diagnosis of PMT. However both stains are highly sensitive. Because of its diffuse strong expression and widespread availability, immunohistochemistry for SSTR2A is useful to confirm the diagnosis of PMT in an appropriate setting particularly if material is limited. Negative staining can serve as an excellent rule out test for this diagnosis.

Paraneoplastic dermatomyositis accompanying nasopharyngeal carcinoma: diagnosis, treatment and prognosis.

Dermatomyositis (DM) is a multisystem inflammatory disorder primarily affecting the skin and muscles. Its pathophysiology is still very poorly understood, but humoral and cellular immune dysregulation is apparent. Diagnosis of DM is based on five criteria: proximal limb muscle weakness, serum muscle enzyme elevation, histopathologic muscle abnormalities on muscle biopsy, electromyographic abnormalities, and clinical inflammatory dermatological manifestations (heliotrope rash, poikiloderma, and inflammatory lesions on the hands and facing joints). DM is frequently associated with certain cancers, and may appear before, concurrent with, or after diagnosis of cancer. DM has been reported to be associated with approximately one per 1000 cases of nasopharyngeal carcinoma. Treatment is based on long-course nonselective immunosuppression, particularly corticosteroids, by general route, even when malignancy is present, but new-targeted therapies may modify the treatment strategy in the near future. Despite iatrogenic immunosuppression, the prognosis of nasopharyngeal cancer is not worse in patients with paraneoplastic DM. We report one case as an illustration of this paraneoplastic course (evolving in parallel with the cancer), and to make an update on the state of knowledge on paraneoplastic DM in such cancers.

Carcinoma tubárico primitivo y polimiositis / Primary primitive fallopian tube carcinoma and polymiositis

Los autores aportan un caso de asociación de un carcinoma tubárico primitivo a una polimiositis. Se trata de una paciente de 53 años, que consultó por dolores pelvianos, metrorragias y leucorreas amarillentas, con una masa pelviana de difícil movilización y móvil a la exploración clínica, y una masa laterouterina derecha con hidrosálpinx en la ecografía pelviana. El diagnóstico definitivo lo aportó el examen ana tomoclínico de la pieza de anexectomía derecha. La histerectomía total sin conservación anexial no dejó residuo tumoral. La paciente perdió contacto con nosotros sin tratamiento complementario y reconsultó 3 años después por una impotencia funcional de los miembros superiores, seguida de los inferiores, mialgias, alteraciones de la deglución y aparición de una adenopatía supraclavicular izquierda. Los exámenes clínicos, paraclínicos y anatomopatológicos mostraron que se trataba de un adenocarcinoma tubárico derecho con recaída ganglionar pelviana y metastásica supraclavicular izquierda, con polimiositis paraneoplásica. La paciente se ha beneficiado de 6 sesiones de quimioterapia, después de radioterapia en el hueco subclavicular izquierdo, a la dosis de 45 Gy. La respuesta al tratamiento ha sido excelente, y la paciente está en remisión completa después de un margen de 50 meses tras el diagnóstico. La asociación de cáncer de la trompa con una polimiositis es excepcional, y es necesaria una terapia antineoplásica rápida para tratar el cáncer y la polimiositis paraneoplásica (AU)

We report a case of a primitive fallopian tube carcinoma associated with polymyositis. A 53­year-old woman consulted for pelvic pain, metrorrhagia, and leukorrhea. Physical examination revealed a renitent and mobile mass in the pelvis. Ultrasonography showed a right lateral uterine mass with hydrosalpinx. Pathological examination of the right annexectomy specimen provided the definitive diagnosis. No residual tumor was found at total hysterectomy with bilateral annexectomy. The patient was lost to follow-up for 3 years without complementary treatment and then consulted again for functional disability first of the upper limbs and subsequently of the lower limbs with myalgia, swallowing disorders and left supraclavicular node enlargement resulting from pelvic relapse of the right fallopian tube adenocarcinoma and left supraclavicular metastasis with paraneoplastic polymyositis. The patient was given 6 courses of chemotherapy with radiotherapy (45 Gy) centered on the left clavicular region. The patient showed excellent response to treatment, and remains in complete remission 50 months after diagnosis. The association of fallopian tube carcinoma with polymyositis is exceptional, requiring rapid treatment effective against the cancer and paraneoplastic polymyositis (AU)

Diagnostic utility of magnetic resonance imaging skeletal survey in a patient with oncogenic osteomalacia.

Oncogenic osteomalacia is a rare paraneoplastic syndrome characterized by hypophosphatemic osteomalacia due to renal phosphate wasting. The same biochemical features are found in patients with X-linked hypophosphatemic rickets/osteomalacia and sporadic hypophosphatemic osteomalacia with unknown etiology. Oncogenic osteomalacia is cured by resection of the responsible tumor. In contrast, patients with other types of hypophosphatemic rickets/osteomalacia need long-term treatment with large doses of active vitamin D3. Therefore, detection of the responsible tumor for oncogenic osteomalacia has great clinical importance. However, there is no standard method for detecting the tumor for oncogenic osteomalacia, and the responsible tumor is often very difficult to be found. We describe a patient with adult-onset osteomalacia due to renal phosphate wasting. Although oncogenic osteomalacia was suspected, cranial, chest, and abdominal computed tomography scanning, urological and otolaryngological examinations, and detailed palpation for soft tissue mass failed to detect the responsible tumor. However, magnetic resonance imaging skeletal survey revealed a tumor in the right femoral bone. Resection of the tumor resulted in normalization of serum phosphate and renal phosphate handling. Because the most frequent causes for oncogenic osteomalacia are tumors in bone or soft tissue, magnetic resonance imaging skeletal survey is a very powerful method for detecting the responsible tumor. Vigorous search for tumors with this method in patients with hypophosphatemic osteomalacia would be helpful not only for proper management of patients, but also for clarifying the identity of sporadic hypophosphatemic osteomalacia.