Hilar and mediastinal sarcoid-like reaction after the treatment of malignant tumors: imaging features and natural course on 18F-FDG-PET/CT.

After the treatment of malignancies, benign sarcoid-like reaction was rarely observed during follow-up. Although sarcoid-like reaction appeared a long time after the treatment of malignancies, it frequently and spontaneously regressed in a relatively short period of time.