Hypophosphatemic osteomalacia: association with prostatic carcinoma

Area of Science:

• Endocrinology
• Oncology
• Nephrology

Background:

• Tumor-induced osteomalacia (TIO) is typically associated with mesenchymal tumors.
• The origin of neoplasms causing TIO was previously thought to be exclusively mesenchymal.

Purpose of the Study:

• To investigate if endodermal malignancies, specifically prostatic carcinoma, can cause TIO.
• To determine if prostatic carcinoma is associated with hypophosphatemia and osteomalacia.

Main Methods:

• Studied patients with coincident hypophosphatemia and prostatic carcinoma.
• Assessed renal phosphate wasting, calcium and phosphate absorption, and phosphate balance.
• Performed bone biopsies to evaluate histomorphologic changes.
• Measured serum levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D.
• Excluded other potential causes of osteomalacia.

Main Results:

• Hypophosphatemic patients exhibited renal phosphate wasting, malabsorption, and negative phosphate balance.
• Bone biopsies confirmed histomorphologic changes indicative of osteomalacia.
• Serum 1,25-dihydroxyvitamin D levels were low, characteristic of TIO.
• Prostatic carcinoma was identified as a potential cause of TIO, despite being an endodermal malignancy.

Conclusions:

• Prostatic carcinoma can induce hypophosphatemic osteomalacia.
• TIO is not exclusively associated with mesenchymal tumors.
• Endodermal malignancies should be considered in the differential diagnosis of TIO.