Oncogenic osteomalacia cured by removal of an organized hematoma

Tumor-induced osteomalacia - a mystery illness beyond aches, pains, and depression

Objective. Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by chronic hypophosphatemia and osteomalacia. We present case of a patient with a protracted clinical course of TIO. TIO profoundly affected every aspect of his life with subsequent profound physical and psychosocial disabilities. Method. The review of a complex clinical presentation, serial laboratory investigations, and imaging modalities of a patient with TIO caused by a mesenchymal tumor. Results. The patient presented with chronic lower back pain, severe bilateral leg weakness, and multiple pathological fractures due to severe osteoporosis. His investigations revealed hypophosphatemia, low 1,25 dihydroxyvitamin D, phosphaturia and normal serum calcium, and parathyroid hormone. Elevated fibroblast growth factor 23 (FGF23) confirmed the diagnosis of TIO and ⁶⁸Ga-DOTATATE-positron emission tomography/computed tomography (PET/CT) imaging correctly identified a tumor in the left femoral head. His clinical features and biochemical abnormalities promptly recovered after successful surgical resection of the mesenchymal tumor. Conclusion. The present case demonstrated the need to extensively investigate causes of generalized bone pain in patients with hypophosphatemia, as TIO is highly curable. Importantly, ⁶⁸Ga-DOTATATE PET/CT imaging successfully identified the FGF23 producing tumor, which was undetectable by conventional imaging, favoring its early use in suspected TIO presentation. The present report highlights the importance of timely diagnosis of this complex medical condition, aiming to improve general awareness and enable better clinical outcomes for this rare disorder.

Application of ultrasound-guided biopsy and percutaneous radiofrequency ablation in 2 cases with phosphaturic mesenchymal tumor and literature review

Tumor-induced osteomalacia (TIO) is a vanishingly rare paraneoplastic syndrome which is usually caused by phosphaturic mesenchymal tumors (PMTs). The conventional treatment for PMTs is total resection, and ultrasound-guided radiofrequency ablation (RFA) can also be used for the treatment of PMTs patients, especially for patients in whom complete resection may lead to serious complications. We report two cases with PMT who presented syndrome with progressive musculoskeletal complaints and performed ultrasound-guided biopsy and RFA. Ultrasound-guided RFA, which is a safe and effective minimally invasive treatment option, appears to be a valuable alternative to surgery for patients presenting with PMT. We are the first reported case of RFA guided by ultrasonography in the treatment of PMT.

Surgical treatment of recurrent spinal phosphaturic mesenchymal tumor-induced osteomalacia: A case report

RATIONALE

Tumor-induced osteomalacia (TIO) is a highly unusual disease with enormous difficulties in clinical diagnosis and curative managements. The objective of this study is to report a very rare case who underwent surgical treatment of recurrent spinal phosphaturic mesenchymal tumor. The management of these unique cases has yet to be further elucidated.

PATIENT CONCERNS

A 52-year-old man presented with a 3-year history of back pain and 1-year history of continuous and progressive systemic bone pain. The patient, who had been diagnosed of TIO for 3 years, received surgical treatment of extended resection of spinal phosphaturic mesenchymal tumor at L5. Somatostatin receptor tomography revealed the expression of somatostatin in the spine increased significantly, with high suspicion of recurrent phosphaturic mesenchymal tumor.

DIAGNOSIS

Magnetic resonance imaging of spine and positron emission tomography-computed tomography showed the mass in L5, which was highly indicative of the recurrent pathogenic tumor. Postoperative pathology confirmed the diagnosis of phosphaturic mesenchymal tumor in the spinal region.

INTERVENTIONS

The patient underwent posterior L5 tumor resection, bone cement reconstruction, L4-S1 spinal canal decompression, and L3-S2 internal fixation.

OUTCOMES

The patient's symptoms improved significantly after the surgery, and we noticed that his hypophosphatemia was successfully corrected after the 2nd operation. Follow-up at 1 month after surgery revealed no recurrence, and the serum phosphorus level of the patient turned to be normal postoperatively. There were no complications associated with the operation during the follow-up period.

LESSONS

Taken together, the lesion's clinical features, imaging results, and pathologic characteristics are unique. Combined efforts of specialists from orthopedics, endocrinology, nuclear medicine, radiology, pathology, and medical oncology led to the successful diagnosis and management of this patient. TIO, although rare, should be part of the differential diagnosis when the patient has a history of hypophosphatemia and systemic multiple bone pain. We recommend surgical treatment of the phosphaturic mesenchymal tumor in the spinal region. Osteoplasty by bone cement may be a treatment option for patients with TIO who cannot undergo appropriate surgery or decline open surgery.

Successful treatment of tumor-induced osteomalacia causing by phosphaturic mesenchymal tumor of the foot

Tumor-induced osteomalacia causing by phosphaturic mesenchymal tumor of the foot is exceedingly rare, thus may bring great challenges to the timely and proper diagnosis and treatment of clinicians. The only definitive management is removal of the phosphaturic mesenchymal tumor completely. The objective of this article is to report 2 unusual cases with tumor-induced osteomalacia causing by phosphaturic mesenchymal tumor of the foot.We describe 2 patients with phosphaturic mesenchymal tumor involving the foot who were successfully treated with tumor resection. On presentation to our institution, the patients both had signs of severe osteomalacia, and the patients' most outstanding complaints were diffuse bone pain, general weakness, and disabled walking. A 53-year-old female underwent surgical excision of pathogenic tumor on the sole of left foot. A 62-year-old female underwent complete excision of pathogenic tumor of right plantar. The patients showed appropriate destruction of the tumor, adequate pain relief, and the elevated blood phosphorus levels compared with the previous status.Surgical resection is the most effective treatment option for patients with tumor-induced osteomalacia who can undergo appropriate surgical treatment. This represents a safe and reasonable approach to sustainably relieve pain and other symptoms with tumor-induced osteomalacia in the foot.

Bone scintigraphic patterns in patients of tumor induced osteomalacia

Tumor induced osteomalacia (TIO) or oncogenic osteomalacia is a rare condition associated with small tumor that secretes one of the phosphaturic hormones, i.e., fibroblast growth factor 23, resulting in abnormal phosphate metabolism. Patients may present with non-specific symptoms leading to delay in the diagnosis. Extensive skeletal involvement is frequently seen due to delay in the diagnosis and treatment. The small sized tumor and unexpected location make the identification of tumor difficult even after diagnosis of osteogenic osteomalacia. The bone scan done for the skeletal involvement may show the presence of metabolic features and the scan findings are a sensitive indicator of metabolic bone disorders. We present the bone scan findings in three patients diagnosed to have TIO.

Tumor-induced osteomalacia: an important cause of adult-onset hypophosphatemic osteomalacia in China: Report of 39 cases and review of the literature

Tumor-induced osteomalacia (TIO) is an acquired form of hypophosphatemia. Tumor resection leads to cure. We investigated the clinical characteristics of TIO, diagnostic methods, and course after tumor resection in Beijing, China, and compared them with 269 previous published reports of TIO. A total of 94 patients with adult-onset hypophosphatemic osteomalacia were seen over a 6-year period (January, 2004 to May, 2010) in Peking Union Medical College Hospital. After physical examination (PE), all patients underwent technetium-99m octreotide scintigraphy ((99) Tc(m) -OCT). Tumors were removed after localization. The results demonstrated that 46 of 94 hypophosphatemic osteomalacia patients had high uptake in (99) Tc(m) -OCT imaging. Forty of them underwent tumor resection with the TIO diagnosis established in 37 patients. In 2 patients, the tumor was discovered on PE but not by (99) Tc(m) -OCT. The gender distribution was equal (M/F = 19/20). Average age was 42 ± 14 years. In 35 patients (90%), the serum phosphorus concentration returned to normal in 5.5 ± 3.0 days after tumor resection. Most of the tumors (85%) were classified as phosphaturic mesenchymal tumor (PMT) or mixed connective tissue variant (PMTMCT). Recurrence of disease was suggested in 3 patients (9%). When combined with the 269 cases reported in the literature, the mean age and sex distribution were similar. The tumors were of bone (40%) and soft tissue (55%) origins, with 42% of the tumors being found in the lower extremities. In summary, TIO is an important cause of adult-onset hypophosphatemia in China. (99) Tc(m) -OCT imaging successfully localized the tumor in the overwhelming majority of patients. Successful removal of tumors leads to cure in most cases, but recurrence should be sought by long-term follow-up.

Tumor-induced osteomalacia

Tumor-induced osteomalacia (TIO) is a rare and fascinating paraneoplastic syndrome in which patients present with bone pain, fractures, and muscle weakness. The cause is high blood levels of the recently identified phosphate and vitamin D-regulating hormone, fibroblast growth factor 23 (FGF23). In TIO, FGF23 is secreted by mesenchymal tumors that are usually benign, but are typically very small and difficult to locate. FGF23 acts primarily at the renal tubule and impairs phosphate reabsorption and 1α-hydroxylation of 25-hydroxyvitamin D, leading to hypophosphatemia and low levels of 1,25-dihydroxy vitamin D. A step-wise approach utilizing functional imaging (F-18 fluorodeoxyglucose positron emission tomography and octreotide scintigraphy) followed by anatomical imaging (computed tomography and/or magnetic resonance imaging), and, if needed, selective venous sampling with measurement of FGF23 is usually successful in locating the tumors. For tumors that cannot be located, medical treatment with phosphate supplements and active vitamin D (calcitriol or alphacalcidiol) is usually successful; however, the medical regimen can be cumbersome and associated with complications. This review summarizes the current understanding of the pathophysiology of the disease and provides guidance in evaluating and treating these patients. Novel imaging modalities and medical treatments, which hold promise for the future, are also reviewed.

Osteomalácia oncogênica: cintilografia com sestamibi-99mTc na localização do tumor

A osteomalácia oncogênica hipofosfatêmica (OOH) é uma síndrome paraneoplásica induzida por tumor, de tecidos mole ou ósseo. Apresenta-se com dor e fraturas, acompanhada de hipofosfatemia, hiperfosfatúria e concentrações plasmáticas de 1,25(OH)2D3 inapropriadamente normais/diminuídas. Após a remoção do tumor, a completa resolução das anormalidades clínicas e bioquímicas é sua maior característica. Uma mulher de 44 anos de idade é descrita no caso com dificuldade para caminhar por causa de dores nos membros inferiores, fraqueza muscular generalizada e hipofosfatemia com relativa hiperfosfatúria. A cintilografia de corpo total com sestamibi-99mTc mostrou acúmulo do radiofármaco no terço superior de coxa esquerda onde pequeno tumor foi detectado no exame pelo ultra-som. Com a retirada do tumor, um lipoma, os sintomas melhoraram após um mês, com recuperação completa ao redor do quarto mês. Neste caso, a cintilografia de corpo inteiro com sestamibi-99mTc foi decisiva na localização do tumor causador da osteomalácia oncogênica.