[A case of pulmonary carcinosarcoma with abnormal uptake in bone scintigraphy]

A 68-year-old man was admitted to our hospital with abnormal chest radiograph shadows. Chest CT showed a large mass with calcification in the right lower lobe. Bone scintigraphy revealed abnormal uptake by the tumor. The biopsy specimen obtained by bronchoscopy and fine-needle aspiration demonstrated no malignancy, and chest radiographs obtained two years before were normal. Right lower lobectomy was performed. Histologically, the tumor was composed of squamous cell carcinoma and osteosarcoma, and the diagnosis was true carcinosarcoma of the lung.