Phosphate depletion syndrome: case report with bone and muscle histology findings and review of the literature

Abstract

A 44-yr-old woman with a 16-yr history of heavy antacid ingestion was evaluated for severe weight loss, weakness, bone pain, and multiple fractures. Laboratory investigation revealed severe hypophosphatemia with undetectable phosphate in the urine. Serum parathyroid hormone (PTH), 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D levels were normal. Transiliac bone biopsy revealed evidence of mineralization defect compatible with hypophosphatemic osteomalacia. Bone densitometry documented decreased bone density with a low mineral content. Management included withdrawal of antacids and provision of phosphate-supplemented enteral nutrition, which resulted in prompt weight gain and resolution of the clinical and biochemical abnormalities. The pathogenesis, diagnosis and histological features of hypophosphatemic osteomalacia are discussed.