FLUORINE-18-FLUORODEOXYGLUCOSE UPTAKE IN RHEUMATOID ARTHRITIS-ASSOCIATED LUNG-DISEASE IN A PATIENT WITH THYROID-CANCER

An F-18-fluorodeoxyglucose (FDG) whole-body PET scan was performed on a thyroid cancer patient with long-standing rheumatoid arthritis who p resented with pulmonary nodules. A recent diagnostic radioiodine whole -body scan was negative. However, the F-18-FDG scan demonstrated inten se uptake in the chest lesions as well as in several joints affected b y rheumatoid arthritis. Fine-needle aspiration of a pulmonary nodule r evealed inflammatory reaction and absence of malignant cells, fungus a nd tuberculous infection. A repeat chest CT scan after 7 mo of steroid therapy showed a marked decrease in the size and number of nodules. I n thyroid cancer patients, F-18-FDG uptake in the lung may not necessa rily represent pulmonary metastases. This case illustrates a benign, u nrelated pathology namely, rheumatoid arthritis-associated lung diseas e.