False positive for malignancy of a lung nodule on FDG PET/CT scans--a lesion with high FDG uptake but stable in size.

A highly F-18 fluorodeoxyglucose-avid lung nodule was stable in both size and metabolic activity over 4 months. This was most likely nonneoplastic because a true tumor would grown in volume overtime. The high level of energy consumption was contributing functional activities or by inflammatory cells. Because the speed of tumor growth is proportional to its energy consumption, we consider the higher the metabolic activity of a lesion, the less likely of malignant if it was stable in size over time.