Tumor-induced osteomalacia (TIO): atypical presentation.

Tumor-induced osteomalacia is a rare acquired condition characterized by phosphaturia, hypophosphatemia and osteomalacia. We report an unusual presentation in a 15-year-old healthy male with a two-week history of cough and chest pain. The chest radiograph showed right middle lobe opacity and chest CT revealed a mass in the extra pleural space. A biopsy showed chondro-myxoidstroma with osteoid formation. Diagnosis was confirmed with the above findings and hypophosphatemia. The patient's symptoms resolved after complete surgical excision of the mass. Tumor-induced osteomalacia, although a rare disorder, can be a diagnostic challenge, especially in patients presenting with atypical symptoms.