Extrathoracic PET/CT findings in thoracic malignancies.

The routine use of integrated positron emission tomography computed tomography in the staging and follow-up of patients diagnosed with non-small-cell lung cancer has improved diagnostic accuracy but many incidental extrathoracic findings are routinely encountered. These include physiologic fluorodeoxy glucose avid foci, normal computed tomography variants, and second primary malignancies, all of which have to be differentiated from extrathoracic metastatic disease. Knowledge of these findings is important for correct staging and identification of second primaries.