Case Report of Tumour-induced Osteomalacia with Parotid Gland Tumour as a Focus

Abstract

Tumour-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, which is characterized by overproduction of FGF23 as a phosphaturic agent leading to chronic phosphaturia and hypophosphatemia, associated with inappropriately normal or low levels of vitamin D. We describe a rare case of a 57-year-old Indian female who presented with bone pains, muscle pains and lower limb weakness. On examination she was found to have hypophosphatemia. Our work up led to the identification of a FGF23 secreting parotid tumour. The tumour responsible for symptoms was a pleomorphic adenoma of the parotid gland. Its complete resection resulted in normalisation of patient's symptoms. Laboratory parameters and microsopic examination further revealed a mesenchymal tumour of mixed connective tissue type.

Keywords

• TIO
• Hypophosphatemia
• FGF-23