Lung cancer in a Thorotrast administered patient.

A 79-year-old man developed small cell carcinoma in the lung 43 years after Thorotrast-injection. The tumor with interstitial fibrosis arose in the periphery of the lung. Thorotrast particles were observed in the liver, spleen, bone marrow, and lymph nodes but not in the lungs. Four other Japanese cases of lung cancer after Thorotrast injection were reviewed.