This 70-year old male smoker presented with both a 2-cm. lesion in the lingula of the left lung and bilateral enlarged hilar lymph nodes evident on CT. A transbronchial biopsy was indeterminate. The patient was referred for a PET scan to differentiate benign vs. malignant status of solitary pulmonary nodule and to assess the degree of mediastinal involvement.

A focal area of increased radiotracer uptake was noted in the left mid-lung, in the area corresponding to the CT abnormality in the lingula. Quantification by Standardized Uptake Value (SUV) was 3.1, indicating hypermetabolism consistent with a malignant process. No other areas of hypermetabolism were noted in the lungs, mediastinum or abdomen.

The patient underwent resection of the left lung lesion, and pathology revealed squamous cell carcinoma, moderately differentiated. There was no metastatic involvement of the mediastinal lymph nodes. PET correctly characterized the nodule and the lymph nodes, thus giving a more accurate staging than had previously been indicated by CT.