False-positive PET scan in a patient with lipoid pneumonia simulating lung cancer.

PURPOSE

Lipoid pneumonia usually presents with alveolar infiltrates or as a nonresolving process. We report a case of lipoid pneumonia that presented as a solitary pulmonary nodule and had a high standard uptake value on PET scan, thereby mimicking a malignant process. This case highlights the presence of false-positive PET imaging in a patient with lipoid pneumonia and Mycobacterium chelonae infection.

MATERIALS AND METHODS

The patient was examined using CT scanning. The nodule was further investigated with a PET scan using F-18 FDG and the standard uptake value was determined.

RESULTS

Histopathology following removal of the nodule confirmed the diagnosis of lipoid pneumonia, and the bronchoalveolar lavage (BAL) was reported as M. chelonae, a rapidly growing mycobacterium (RGM).

CONCLUSION

Lipoid pneumonia can present as a PET-positive lung nodule and should be considered in the differential diagnosis and workup of a solitary pulmonary nodule.