Octreotide Therapy for Tumor-Induced Osteomalacia

Abstract

Tumor-induced osteomalacia (also known as oncogenic osteomalacia)¹ is a rare disorder characterized by phosphaturia, hypophosphatemia, and osteomalacia mimicking the clinical phenotype of either X-linked² or autosomal dominant³ hereditary hypophosphatemic rickets. Tumor-induced osteomalacia develops because of tumors that are predominantly of benign mesenchymal origin⁴ but that may occasionally be malignant, as was recently reported.⁵ Surgical removal of the tumor relieves all symptoms. Hemangiopericytoma is the most dominant histologic entity in tumor-induced osteomalacia.^4,6 Paraneoplastic secretion by the tumor of an unknown factor or factors — termed “phosphatonins” — causing renal tubular phosphate wasting has been proposed as the pathogenic mechanism.⁷