Occult nasal sinus tumours causing oncogenic osteomalacia

Area of Science:

• Endocrinology
• Oncology
• Metabolic Bone Disease

Background:

• Oncogenic osteomalacia (OOM) is a rare paraneoplastic syndrome causing metabolic bone disease.
• It is characterized by renal phosphate wasting due to tumor-secreted factors, primarily fibroblast growth factor 23 (FGF23).
• Delayed diagnosis is common, leading to prolonged morbidity.

Observation:

• This study reports on 9 patients diagnosed with OOM.
• Two patients had occult nasal sinus tumors, underscoring the need for thorough imaging.
• One patient showed a rise in FGF23 post-surgery, preceding metastatic pulmonary disease.

Findings:

• The median symptom duration before diagnosis and treatment was 6 years.
• Serum FGF23 levels are valuable for diagnosing OOM and monitoring treatment response.
• Nasal sinus imaging should be considered in the work-up of suspected OOM.

Implications:

• Early and accurate diagnosis of OOM is essential for timely surgical intervention and cure.
• Serum phosphate measurement is critical for patients with unexplained bone or muscle symptoms.
• Monitoring FGF23 levels can aid in detecting disease recurrence or progression.