Oncogenic osteomalacia.

A 59-year-old gentleman presented with symptoms of progressively worsening low back pain associated with difficulty in rising from a squat over a period of two years. Biochemical tests confirmed the initial clinical diagnosis of osteomalacia. Blood pool scanning revealed a focal hot spot on the site of the clinically visible swelling close to the metacarpo-phalangeal joint of the left index finger. The biopsy of the specimen obtained by excision was reported to be consistent with a phosphaturic mesenchymal tumour. The patient had complete resolution of symptoms six months following excision of the lesion.