Oncogenic osteomalacia: evidence for a humoral phosphaturic factor.

Abstract

Oncogenic osteomalacia is a syndrome characterized by phosphaturia, hypophosphatemia, reduced vitamin D levels, and osteomalacia. The cause is not known, but all patients have had a tumor; usually of mesenchymal origin. Removal of the tumor reverses the metabolic abnormalities. We report a patient with osteomalacia, severe hypophosphatemia, elevated alkaline phosphatase, low 1,25-dihydroxyvitamin D3, and phosphaturia. A tumor was identified in the infratemporal fossa. The tumor was removed, and all of the biochemical abnormalities resolved over the subsequent 8 months. The bone density returned to normal values. The tumor had the appearance of a paraganglioma and was used to establish a cell culture line called JH-55. Electron microscopy of the original tumor and the JH-55 cells demonstrated the presence of neurosecretory granules. A bioassay using opossum kidney cells was used to evaluate phosphate transport. Conditioned medium from the JH-55 cells inhibited phosphate reabsorption by the kidney tubular cells. Maximal inhibition required a 24-h incubation period and was not altered by the presence of an inhibitor of protein synthesis (10 micrograms/mL cycloheximide). Immunoassays revealed no detectable PTH-related peptide or intact PTH in the JH-55 medium. The cause of this paraneoplastic syndrome is not known, but all of the evidence is consistent with the action of a hormone that produces phosphaturia. This putative factor is distinct from other hormones that cause phosphaturia.

• Authors: G E Wilkins, S Granleese, R G Hegele, J Holden, D W Anderson, G P Bondy
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 80 Issue 5 Pg. 1628-34 (May 1995) ISSN: 0021-972X [Print] United States
• PMID: 7745010 (Publication Type: Case Reports, Journal Article)

Chemical References

• Phosphates

Topics

• Animals
• Biological Assay
• Biological Transport
• Humans
• Kidney (cytology, metabolism)
• Male
• Middle Aged
• Opossums
• Osteomalacia (etiology)
• Phosphates (metabolism, urine)
• Skull Neoplasms (complications, metabolism, pathology)
• Tomography, X-Ray Computed
• Tumor Cells, Cultured