cholecalciferol and Paraneoplastic-Syndromes

Oncogenic osteomalacia (OOM) is a rare paraneoplastic syndrome induced by tumor produced phosphaturic factors, i.e. phosphatonins. The disorder is characterized by renal tubular phosphate loss, secondary to this process hypophosphatemia and defective production of active form of vitamin D. The clinical course of oncogenic osteomalacia is characterized by bone pain, pathological fractures, muscle weakness and general fatigue. Osteomalacia-associated tumors are usually located in the upper and lower limbs, with half of the lesions primarily situated in the bones. Most of them are small, slow-growing tumors. Their insignificant size and various location coupled with rare occurrence of the disease and non-specificity of clinical symptoms lead to difficulties in reaching a diagnosis, which is often time-consuming and requires a number of additional tests. The average time between the appearance of the first symptoms and the establishment of an accurate diagnosis and the beginning of treatment is over 2.5 years. The aim of this study is to discuss the pathophysiology of disease symptoms, pathomorphology of tumors, diagnostic methods and treatment of oncogenic osteomalacia.

Topics: Biopsy; Bone and Bones; Cholecalciferol; Diagnostic Imaging; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Fractures, Spontaneous; Humans; Hypophosphatemia; Neoplasms, Connective Tissue; Osteomalacia; Pain; Paraneoplastic Syndromes; Somatostatin

Topics: Animals; Cholecalciferol; Diagnosis, Differential; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Hypophosphatemia; Neoplasms; Osteomalacia; Paraneoplastic Syndromes; Prognosis; Rickets

Tumor-induced osteomalacia is a rare paraneoplastic syndrome characterized by hypophosphatemia and inappropriately normal or low 1,25-dihydroxyvitamin D.. Here, we report a 6-year postoperative follow-up of a patient with oncogenic osteomalacia with a distinctive skeletal manifestation. The latter was characterized by an almost linear lytic lesion of a few millimeters with irregular borders, mainly involving the trabecular compartment but extending into cortical shell, located in the middle third of the right fibula. Six years after tumor resection, a sclerotic repair with a complete recovery was observed. Furthermore, we monitored a striking increase in bone mineral density throughout the observation period, reaching a peak of 73% over basal values at lumbar spine after 2 years; at total femur and radius, the peak was 47.5 and 4.6% respectively, after 4 years from tumor resection.. We report for the first time that an osteolytic lesion may be part of the skeletal involvement in tumor-induced osteomalacia.

Topics: Bone Density; Bone Density Conservation Agents; Calcium, Dietary; Cholecalciferol; Combined Modality Therapy; Dietary Supplements; Female; Fibula; Fractures, Stress; Humans; Middle Aged; Nasopharyngeal Neoplasms; Neoplasms, Connective Tissue; Osteomalacia; Paraneoplastic Syndromes; Postoperative Complications; Radiography; Treatment Outcome; Up-Regulation

We report a 28-year-old woman who presented with severe proximal muscle weakness secondary to paraneoplastic hypophosphatemia and associated with recurrent neuroblastoma. The biochemical findings included hyperphosphaturia, a reduced serum level of 1,25-dihydroxyvitamin-D3, elevated alkaline phosphatase and normocalcemia which are pathognomic for paraneoplastic hypophosphatemia. Following systemic chemotherapy and supplementation of 1,25-dihydroxyvitamin-D3 a complete remission of the neuroblastoma was achieved and all features of the paraneoplastic hypophosphatemia gradually disappeared. In the differential diagnosis of muscle weakness, hypophosphatemia should be included. Paraneoplastic hypophosphatemia associated with metastatic neuroblastoma has not been reported previously. Diagnosis, mechanism and therapy of paraneoplastic hypophosphatemia are shortly reviewed.

Topics: Adult; Alkaline Phosphatase; Antineoplastic Combined Chemotherapy Protocols; Biopsy; Calcium; Cholecalciferol; Female; Follow-Up Studies; Humans; Hypophosphatemia; Magnetic Resonance Imaging; Muscle Weakness; Neoplasm Recurrence, Local; Neuroblastoma; Paraneoplastic Syndromes; Spinal Neoplasms

Topics: Animals; Bone Neoplasms; Cholecalciferol; Cyclic AMP; Diagnosis, Differential; Humans; Hypercalcemia; Hyperparathyroidism; Mice; Neoplasms; Paraneoplastic Syndromes; Parathyroid Hormone; Peptides