Extended curettage for tumour-induced osteomalacia in the bone.

BACKGROUND: extended curettage is generally used to treat infiltrative bone tumours. However, the extent of the curettage performed in previous studies remains unclear. This study aimed to investigate the efficacy of extended curettage for bone tumour-induced osteomalacia. METHODS: we included 12 patients with tumour-induced osteomalacia who underwent extended curettage at our hospital between 2000 and 2022. Extended curettage was applied in cases where tumour resection could cause functional impairment or necessitate complex reconstruction. We investigated patients' clinical and oncological outcomes. RESULTS: patients had a mean age of 55 (24-81) years, and the median follow-up duration after surgery was 3.9 (1.0-14.0) years. The causative tumours were located in the pelvis and lumbar spine. Imaging revealed the tumours to be of the sclerotic, intertrabecular, lytic and mixed types. Intraoperative 3D fluoroscopy was used in 10 patients. Extended curettage with high-speed burring and adjuvant therapy with cauterization using an electric scalpel and ethanol resulted in a remission rate of 83%; no recurrence or metastasis was observed in cases of early postoperative biochemical remission. In cases where the causative tumour was at the lumbar spine and ischium close to the acetabulum, no postoperative biochemical remission was observed, and conservative treatment was continued. Except for one patient with a tumour in the lumbar spine, all patients could walk without a cane. CONCLUSIONS: extended curettage for bone tumour-induced osteomalacia is oncologically and functionally favourable, especially in cases where resection of the causative tumour could cause functional impairment or necessitate complex reconstruction.

Tumor-induced osteomalacia characterized by "painful knee joint with difficulty in moving": a case report.

BACKGROUND: Tumor-related osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by severe hypophosphatemia and osteomalacia. The diagnosis of TIO can be very difficult because of its nonspecific nature of clinical manifestations. Here we reported a case of young TIO patient with "painful knee joint with difficulty in moving" to improve the clinical diagnosis and treatment levels. CASE PRESENTATION: The patient's clinical features were consistent with TIO. A tumor was successfully located in left tibial by 68Ga-DOTATATE PET/CT, and then was surgically resected. Upon pathologic assessment, the tumor was diagnosed as phosphaturia stromal tumor (PMT) with positive Vim staining. After the surgery, serum phosphate level rapidly recovered and symptoms significantly improved. CONCLUSION: TIO should be considered in patients with chronically hypophosphorus osteomalacia in the setting of no family history. Early removal of the responsible tumors is clinically essential for the treatment, and imaging examination is of great significance for tumor localization.

Total hip arthroplasty for treatment of femoral neck fracture due to hypophosphatemic osteomalacia: a retrospective case series with mean follow-up of five years.

BACKGROUND: To retrospectively characterize the clinical characteristics and efficacy of total hip arthroplasty and the important factors needing attention in hypophosphatemic osteomalacia (HO) patients with hip involvement. PATIENTS AND METHODS: We performed a review of seven patients (two women and five men) referred to our clinic with a final diagnosis of HO who received total hip arthroplasty between 2010 and 2018. Five patients (Group 1) received proper medical management with or without aetiologic therapy, while the other two patients (Group 2) did not receive due to misdiagnosis. The mean follow-up duration was 5.1 ± 2.0 years. RESULTS: The patients in Group 1 had significant relief of pain and improved laboratory results. The mean Harris Hip Score of Group 1 increased from 44.2 ± 6.0 to 94.0 ± 3.0, and the mean VAS score decreased from 8.8 ± 0.4 to 1.8 ± 0.7. However, the progressive extensive pain score in Group 2 had no obvious improvement, with the Harris Hip Score increasing from 45.5 ± 0.5 to 60 ± 28.0 and the VAS score decreasing from 9.0 ± 1.0 to 6.5 ± 2.5. CONCLUSION: THA appears to be an effective method for hip arthritis or joint deformities resulting from hypophosphatemic osteomalacia. A satisfactory outcome of the surgery depends on the early etiological identification, the treatment of hypophosphatemia, a careful operation, and the operative strategies, as well as proper medical treatment.

Phosphaturic Mesenchymal Tumors of the Sinonasal Area and Skull Base: Experience at a Single Institution.

OBJECTIVES: Phosphaturic mesenchymal tumor (PMT) is a rare, polymorphous neoplasm with a highly variable presentation and natural history and unpredictable clinical course. The primary objective was to describe our clinical experience with and management of 4 markedly different cases of sinonasal and skull base PMT. METHODS: A retrospective case series with chart review, and relevant literature review, was performed at a tertiary academic medical center between 1998 and 2020. Adult patients treated for PMTs of the sinonasal area and skull base were included. Our main outcome measures included postoperative laboratory findings and radiological evidence of disease remission. RESULTS: Four patients (2 Males, 2 Females; Mean Age: 63.5 years) with PMTs of the skull base have been managed at our institution since 1998. Patient presentations varied, ranging from severe phosphorus wasting and osteoporosis to symptoms secondary to mass effect, including nasal obstruction and rhinorrhea. All 4 patients were eventually found to have elevated levels of fibroblast growth factor 23. Tumors were located in the sinonasal area (right frontal sinus, right ethmoid sinus, and right nasal cavity, respectively) in 3 patients and in the lateral skull base (right jugular foramen) in 1 patient. All 4 patients underwent complete surgical resection of their tumors. PMT tissue pathology was confirmed in all cases. Gross total resection was achieved in all patients. There was no chemical or radiological evidence of disease recurrence in any patients at follow-up. CONCLUSIONS: The presentation of skull base PMT is variable, and it may mimic other mass pathologies of the head and neck. Complete surgical resection with negative margins is potentially curative.

Management of intrathoracic phosphaturic mesenchymal tumor by nonintubated uniportal video-assisted thoracic surgery in a fragile patient.

BACKGROUND: Phosphaturic mesenchymal tumors are rare neoplasms, frequently presenting with osteomalacia. These neoplasms usually grow at a slow rate and are associated with unspecific symptoms. CASE: In this study, we present the case of a 70-year-old woman who had been suffering from musculoskeletal pain, hypophosphatemia, and spontaneous fractures. Positron emission tomography with Gallium showed increase uptake in a subpleural lesion. CONCLUSION: The patient underwent surgical excision of the subpleural lesion with a non-intubated uniportal video-assisted thoracoscopic surgery approach.

Prolonged Hypophosphatemia and Intensive Care After Curative Surgery of Tumor Induced Osteomalacia: A Case Report.

Introduction: Rare FGF23-producing mesenchymal tumors lead to paraneoplastic tumor-induced osteomalacia (TIO) presenting with phosphate wasting, hypophosphatemia, chronic hypomineralization of the bone, fragility fractures and muscle weakness. Diagnosis of TIO requires exclusion of other etiologies and careful search for a mesenchymal tumor that often is very small and can appear anywhere in the body. Surgical removal of the tumor is the only definitive treatment of TIO. Surgical complications due to chronic hypophosphatemia are not well recognized. Case Description: The current case describes severe fragility fractures in a 58-year-old woman, who lost her ability to walk and was bedridden for two years. First, the initial diagnostic laboratory work-up did not include serum phosphorus measurements, second, the suspicion of adverse effects of pioglitazone as an underlying cause delayed correct diagnosis for at least two years. After biochemical discovery of hyperphosphaturic hypophosphatemia at a tertiary referral centre, a FGF23-producing tumor of the mandible was discovered on physical examination, and then surgically removed. Postoperatively, severe hypophosphatemia and muscle weakness prolonged the need for ventilation support, intensive care and phosphate supplementation. After two years of rehabilitation, the patient was able to walk short distances. The tumor has not recurred, and serum phosphate concentration has remained within normal limits during 3.5 years of follow-up. Conclusions: The case report illustrates knowledge gaps in the diagnostic work-up of rare causes of low bone mass and fragility fractures. Compared to other low phosphate conditions, surgical recovery from TIO-induced hypophosphatemia warrants special attention. Increased alkaline phosphatase concentration may indicate impaired postsurgical recovery due to prolonged hypophosphatemia, underlining the need for proactive perioperative correction of hypophosphatemia.

Persistent phosphaturic mesenchymal tumor causing tumor-induced osteomalacia treated with image-guided ablation.

Phosphaturic mesenchymal tumors (PMTs) can present with vague symptoms of diffuse bone pain with pathologic fractures that often lead to a delayed diagnosis. We present a 60-year-old patient with a PMT that was persistently hypophosphatemic after resection, who was then successfully treated with cryoablation of the tumor. Tumor-induced osteomalacia (TIO) is a rare cause of hypophosphatemia characterized by vague symptoms of gradual muscle weakness and diffuse bone pain with pathologic fractures that often lead to a delayed diagnosis. This condition is usually caused by benign phosphaturic mesenchymal tumors (PMTs). Here, we present a case of persistent PMT after surgical resection treated with image-guided ablation. We present the patient's clinical examinations and laboratory findings (phosphorus, 1,25 (OH)2D, FGF-23, Intact PTH). Representative histologic images of a PMT are also presented. A 61-year-old male was evaluated for persistent hypophosphatemia and presumed osteomalacia. Six years earlier, he underwent surgical excision of a left ischial mass after presenting with TIO. The pathology was consistent with a PMT; however, hypophosphatemia persisted suggesting incomplete resection. He was treated with calcitriol and phosphate salts. A PET Ga68 dotatate scan of the patient revealed an avid left ischial mixed lytic and sclerotic lesions with marked amount of radiotracer uptake, suggesting persistent tumor. The patient was resistant to re-excision of the tumor due to the extended recovery period from his prior surgery and was treated instead with cryoablation of the tumor. His biochemical findings of hypophosphatemia and elevated FGF23 resolved after the ablation and have remained normal for 5 months after surgery. In patients with TIO, wide surgical excision is the treatment of choice. When this is not possible, image-guided ablation is an alternative therapeutic option.

Nasal hemangiopericytoma presenting with oncogenic osteomalasia: A case report and literature review.

Sinonasal type hemangiopericytoma is a rare soft tissue tumor. Oncogenic osteomalacia (tumor-induced osteomalacia) is a rare syndrome that develops especially due to benign mesenchymal tumors. Nonspecific general bone pain and weakness delay the diagnosis and treatment of oncogenic osteomalacia, and it is difficult to determine the localization of the primary tumor causing oncogenic osteomalacia. A 43-year-old male patient with nasal hemangiopericytoma with symptoms of oncogenic osteomalacia is presented. The patient had musculoskeletal complaints at first and was diagnosed with lumbar disc herniation and surgery was performed. When his complaints recurred 1 year later, he was re-evaluated and diagnosed with hypophosphatemic osteomalacia. Despite the various treatments he received, his complaints did not decrease but increased, so a detailed examination was decided. When the positive PHEX mutation and very high fibroblast growth factor 23 level were detected, PET-CT imaging was performed with a pre-diagnosis of possible oncogenic osteomalacia, but no finding was found. Then he was evaluated with Ga-68 DOTATATE, and the soft tissue mass filling the right ethmoidal sinus was detected. Due to the relation of the mass with surrounding structures, it was considered unsuitable for total excision and incomplete surgical excision was performed. Pathologic evaluation revealed sinonasal type hemangiopericytoma (glomangiopericytoma). A significant remission in the patient's complaints was observed after the operation. Young patients with osteomalacia with unknown causes should be evaluated for malignancy, and screening and further examinations should be performed.

Clinical Characteristics and Surgical Outcomes of Sinonasal Lesions Associated With Tumor-Induced Osteomalacia.

OBJECTIVE: To investigate the clinical characteristics and surgical outcomes of sinonasal tumors associated with tumor-induced osteomalacia (TIO). STUDY DESIGN: Retrospective case series. SETTING: Single tertiary center. METHODS: We studied the clinical characteristics and surgical outcomes of 43 patients (22 male, 21 female) who had lesions in the nasal cavity and paranasal sinus associated with TIO and underwent surgery between August 2006 and November 2019. RESULTS: The mean ± SD duration between the onset of symptoms and surgery was 3.9 ± 2.6 years. The most common tumor site was the ethmoid sinus (76.7%), and the skull base was involved in 12 cases. Phosphaturic mesenchymal tumors were diagnosed in 41 patients, among whom there was 1 multifocal case. Another 2 cases involved odontogenic fibroma and hemangiofibroma, respectively. Serum phosphorus normalized in 39 cases within 4.4 ± 2.3 days, and serum fibroblastic growth factor 23 normalized within 1 day; clinical symptoms, however, gradually improved within several months after the first operation. There was no significant difference in the recovery rate between endoscopic and open surgery (P = 0.639). Two patients with recurrent cases and 2 with nonremission cases recovered after a sinonasal reoperation. The patient with a multifocal case recovered after the resection of the tumors in the ethmoid sinus and mandible. The overall recovery rate was 97.7%. CONCLUSION: Most sinonasal tumors associated with TIO are located in the ethmoid sinus, and the skull base is involved in some cases. Complete excision of the tumor leads to recovery, and endoscopic surgery could achieve recovery rates similar to those of open surgery.

Surgical Treatment and Outcomes for Sinonasal and Skull Base Phosphaturic Mesenchymal Tumors.

OBJECTIVE: To describe our clinical experience with surgical treatments for sinonasal phosphaturic mesenchymal tumors diagnosed at our institution. STUDY DESIGN: Retrospective case series. SETTING: Affiliated Sixth People's Hospital, Shanghai Jiao Tong University. SUBJECTS AND METHODS: We retrospectively reviewed the medical records of 10 patients diagnosed with phosphaturic mesenchymal tumors associated with tumor-induced osteomalacia between December 2014 and October 2019. RESULTS: There were 4 men and 6 women with a disease course of 1 to 19 years. All patients exhibited hypophosphatemia and tumor-induced osteomalacia. The tumor was located in the sinonasal region, frontal bone, and temporal bone in 8 patients, 1 patient, and 1 patient, respectively. Technetium-99m octreotide scintigraphy was used for tumor localization in 4 cases. Six patients underwent endoscopic resection; the remaining 4 underwent unilateral transorbital anterior and posterior ethmoid artery ligation + endoscopic resection, endoscopic resection + skull base repair, internal carotid artery stenting + transcatheter arterial embolization + temporal bone tumor excision + adipose tissue plugging, and endoscopic resection + transfrontal craniotomy (n = 1 each). Two patients had a history of incomplete endoscopic resection. All patients achieved clinical remission and normalized biochemical indices after surgery. Only 1 patient developed recurrence and died of a brain hernia. CONCLUSIONS: A diagnosis of sinonasal phosphaturic mesenchymal tumors should be based on a combination of clinical, imaging, and pathological findings. Technetium-99m octreotide scintigraphy helps in locating the tumor. Complete surgical excision guarantees clinical remission, and preoperative transcatheter arterial embolization or feeding artery ligation may reduce intraoperative bleeding in cases of highly vascularized tumors.

Treatment and outcomes of tumor-induced osteomalacia associated with phosphaturic mesenchymal tumors: retrospective review of 12 patients.

BACKGROUND: Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by severe hypophosphatemia and osteomalacia. Nonspecific symptoms make the diagnosis elusive. In addition, locating the responsible tumor(s) is challenging. The aim of this study was to investigate the clinical management and outcomes of TIO. METHODS: The clinical features, diagnostic procedures, treatment, and outcomes of 12 patients were reviewed retrospectively. RESULTS: The cohort comprised six men and six women (mean age 45.5 ± 9.9 years, range 23-61 years). The mean duration of disease was 3.7 ± 2.6 years. All patients manifested progressive bone pain, muscle weakness, and/or difficulty walking. Serum phosphorus concentrations were low in all patients (mean 0.42 ± 0.12 mmol/L). Technetium-99m octreotide scintigraphy was performed in 11 patients and showed lesions in the right distal femur, left femoral head, and right tibial plateau, respectively, in three patients. Magnetic resonance imaging (MRI) was negative for lesions in one patient. Two patients underwent biopsies that showed negative histopathology. Two patients, at 2 years and 8 months, respectively, after having negative technetium-99m octreotide studies, underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (CT), which revealed lesions in the sacrum and soft tissue of the left palm, respectively. One tumor was detected by CT and MRI. Overall, lesion sites were the head (two patients, 16.7%), thoracic and lumbar region (two, 16.7%), pelvis (three, 25%), lower limbs (four, 33.3%), and upper limbs (one, 8.3%). All patients underwent surgery, and histopathology showed phosphaturic mesenchymal tumors in each. Postoperatively, serum phosphorus concentrations normalized within 2-7 days in 11 patients. With follow-ups of 1-41 months, surgery was effective in 10 patients. One patient developed local recurrence and another had metastases. CONCLUSIONS: Locating tumors responsible for tumor-induced osteomalacia is often challenging. Although complete tumor resection confers a good prognosis in most patients, surveillance for recurrence and metastasis is necessary. Before surgery or when surgery is not indicated, oral phosphate can alleviate symptoms and metabolic imbalance.

Three-dimensional fluoroscopic navigation-assisted surgery for tumors in patients with tumor-induced osteomalacia in the bones.

PURPOSE: Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome usually caused by phosphaturic mesenchymal tumors. Segmental resection has been recommended for these tumors in the bones because curettage was found to be associated with a high local recurrence rate. Navigation-assisted surgery provides radiological information to guide the surgeon during surgery. No previous study has reported on the efficacy of navigation-assisted surgery for tumors in patients with TIO. Therefore, the present study aimed to evaluate the efficacy of navigation-assisted surgery for tumors in patients with TIO. METHODS: The study included seven patients with TIO who were treated between January 2003 and December 2014 at our hospital. All patients underwent surgical treatment with or without the use of a 3-dimensional (3D) fluoroscopy-based navigation system. The laboratory data and oncological outcomes were evaluated. RESULTS: The follow-up period was 8-128 months. The tumors were located at the femur (n = 4), ischium, spine and ilium (n = 1). Of the seven patients, five underwent navigation-assisted surgery and two underwent surgery without navigation assistance. In the two patients who underwent surgery without navigation assistance, a complete cure was not obtained and osteomalacia did not resolve. One of these two patients and the other five patients who underwent navigation-assisted surgery, one patient had incomplete resection due to massive invasion of the tumor into the spinal canal, but five patients achieved complete excision and recovered from osteomalacia. CONCLUSIONS: Navigation-assisted surgery using a 3D fluoroscopy-based navigation system is effective for tumors in patients with TIO.

En bloc resection for treatment of tumor-induced osteomalacia: a case presentation and a systematic review.

BACKGROUND: Tumor-induced osteomalacia (TIO) is a rare disorder, which is commonly found in craniofacial locations and in the extremities. To the best of our knowledge, only 16 cases have been described in the spine, and this is the first report to describe a case of patient with TIO in the thoracic spine combined with a mesenchymal hamartoma which had confused the therapeutic strategies to date. CASE DESCRIPTION: We report the case of a 60-year-old patient with hypophosphatemia and presented with limb weakness. Treating with phosphate did not correct the hypophosphatemia and an (111)In pentetreotide scintigraphy (octreotide scan) revealed an increased uptake at the right forearm. The tumor was resected totally, and the histopathology revealed a mesenchymal hamartoma, but we noticed that hypophosphatemia was not corrected after the tumor resection. Then a whole-body magnetic resonance imaging (WB-MRI) was performed and the results revealed tumorous tissues at the right T1 vertebral pedicle. The tumor was removed with an en bloc method, and the pathology showed phosphaturic mesenchymal tumor. Follow-up at 1 year after surgery revealed no recurrence, and the serum phosphorus level of the patient was normal. CONCLUSIONS: Tumor-induced osteomalacia is exceedingly rare with only 16 cases in spine published in the literature. It is difficult to find and leads to years of suffering debilitating complications. In this regard, the WB-MRI is a better method to locate the real tumor. Treating with phosphate can only relieve symptoms, and a complete surgical removal remains the gold standard treatment.

Radiofrequency ablation, an effective modality of treatment in tumor-induced osteomalacia: a case series of three patients.

CONTEXT: Tumor-induced osteomalacia is curable if the tumors can be totally excised. However, when the tumors are present in locations that make surgery disproportionately risky, the need for less invasive strategies like radiofrequency ablation (RFA) is realized. PATIENTS AND METHODS: We describe three patients with suspected tumor-induced osteomalacia who were treated in our department between 2006 and 2013 with tumors in surgically difficult locations and were subjected to single or multiple sessions of RFA. The response was documented in terms of symptomatic improvement, phosphorus normalization, and follow-up (99m)Technitium-labelled hydrazinonicotinyl-Tyr3-octreotide ((99m)Tc HYNIC TOC) scan. RESULTS: Two of the three individuals, patient A (with a 1.5 × 1.2-cm lesion in the head of the right femur) and patient B (with a 1.3 × 1.2-cm lesion on the endosteal surface of the shaft of the left femur), achieved complete remission with single sessions of RFA. Three months after the procedure, (99m)Tc HYNIC TOC scans revealed the absence of uptake at the previous sites, corroborating with the clinical improvement and phosphorus normalization. Patient C had a large 5.6 × 6.5-cm complex lesion in the lower end of the left femur with irregular margins, loculations, and bone grafts placed in previous surgery. He failed to achieve remission after multiple sessions of RFA due to the complex nature of the lesion, although the tumor burden was reduced significantly as documented on serial (99m)Tc HYNIC TOC scans. CONCLUSIONS: Although surgery remains the treatment of choice, RFA could be an effective, less invasive, and safe modality of treatment in judiciously selected patients.

Bilateral femoral neck insufficiency fractures in pregnancy.

Bilateral femoral neck insufficiency fracture due to osteomalacia in pregnancy is an extremely rare condition. In this article, we report a 22-year-old female case with bilateral femoral neck fractures in whom the diagnosis was delayed due to the avoidance of ionising radiation and managing hip complaints by conservatively in pregnancy. She was treated surgically with internal fixation using cannulated screws and received medical treatment for vitamin D deficiency.

Evaluation of tumor-induced osteomalacia with 111In-pentetreotide scintigraphy.

In cases of nonhereditary osteomalacia associated with hypophosphatemia and inadequate response to vitamin D supplementation, one should consider the possibility of tumor-induced osteomalacia, a paraneoplastic syndrome caused by small mesenchymal tumors often found in obscure locations. We present a case of tumor-induced osteomalacia in which (111)In-pentetreotide scintigraphy aided in accurate localization of the culprit brachial plexus tumor and cure after resection.