To highlight the clinical presentation and management of a rare case of oncogenic osteomalacia due to an ethmoid sinus tumour.

We examined the case records of a 55-year-old man who presented with progressive fatigue, weakness and bone pain, and noted the clinical presentation, laboratory investigations, computed tomography findings, operative notes and follow-up details.

Oncogenic osteomalacia secondary to a paranasal sinus neoplasm is a rare entity. The causative tumour is often occult and may be missed by routine clinical examination. This case report illustrates the appropriate pattern of evaluation and management to ensure a successful outcome.

Oncogenic osteomalacia, or tumour-induced osteomalacia, is an uncommon cause of osteomalacia. It has been reported to occur in patients with hypophosphataemia due to excess renal phosphate excretion secondary to mesenchymal tumours. Occurrence of this pathological process in the head and neck is extremely rare.

Case report and literature review.

We present a case of a 73-year-old woman with tumour-induced osteomalacia. She was initially followed by the endocrinologists for osteomalacia and pathological fractures. An indium-111 pentetreotide scan showed activity in the left pterygopalatine fossa. A mass was endoscopically resected, and the histopathological appearance was consistent with a haemangiopericytoma. Following surgery, the patient's hypophosphataemia and vitamin D deficiency corrected and her symptoms resolved.

Oncogenic osteomalacia, or tumour-induced osteomalacia, is a rare entity in the head and neck. Current research is elucidating the mechanism by which phosphaturic wasting occurs. In most patients, symptoms resolve once the offending tumour is removed.

X-linked hypophosphataemic osteomalacia is the most common of the genetically determined forms of osteomalacia. The occurrence of hearing loss in X-linked hypophosphataemic osteomalacia has been known since 1984. However, observations on the progression of such hearing loss, and suggestions regarding possible therapy, have not previously been published.

Case report of a patient with X-linked hypophosphataemic osteomalacia and hearing loss, with three years' audiological follow up, description of empirical therapy and literature review.

The patient presented with fluctuating hearing. An audiogram showed mild to severe sensorineural hearing loss mainly in the low and high frequencies. A temporary improvement of 20–40 dB after steroid therapy was observed. Four weeks later, hearing had deteriorated again, mainly in the low frequencies. After one year of fluctuating hearing levels, stabilisation occurred.

In X-linked hypophosphataemic osteomalacia, hearing loss occurs predominantly in the low and high frequencies. The hearing loss type and progression pattern point to an endolymphatic hydrops as the pathogenetic mechanism. Steroid therapy may be of some benefit.