LOCALIZED FORM OF BRONCHIOLOALVEOLAR CARCINOMA - FDG PET FINDINGS

OBJECTIVE. The aim of our study was to describe F-18-fluorodeoxyglucos e (FDG) positron emission tomography (PET) findings of a localized for m of bronchioloalveolar carcinoma and to compare those findings with o ther cell types of lung cancer. SUBJECTS AND METHODS. FDG PET was perf ormed in 48 patients with lune cancer. The patients had carcinomas of various cell types: bronchioloalveolar carcinoma (n = 9), squamous cel l carcinoma (n = 11), adenocarcinoma (n = 22), and other cell types (n = 6). Using FDG PET, we compared peak standardized uptake values amon g the various cell types of lung cancer. CT and pathologic findings fo r patients with bronchioloalveolar carcinoma were also reviewed, RESUL TS. Overall, 48 malignant tumors showed a mean peak standardized uptak e value of 8.0 +/- 4.1. The mean peak standardized uptake value was 3. 5 +/- 2.2 for bronchioloalveolar carcinoma, 10.8 +/- 4.4 for squamous cell carcinoma, and 8.8 +/- 3.2 for adenocarcinoma. The mean peak stan dardized uptake value for bronchioloalveolar carcinoma was significant ly lower than that for adenocarcinoma and squamous cell carcinoma (p < .001). On high-resolution CT scans, bronchioloalveolar carcinomas app eared as areas of ground-glass opacity (n = 4), as nodules (n = 2), as masses (n = 2), and as a ground-glass opacity plus consolidation (n = 1). On pathologic examination, bronchioloalveolar carcinomas were wel l differentiated, having moderate degrees of nuclear atypism, mild deg rees of mitotic figure, desmoplasia, and necrosis. CONCLUSION. The loc alized form of bronchioloalveolar carcinoma shows significantly lower peak standardized uptake values than do other lung carcinomas. Thus, b ronchioloalveolar carcinoma can be a potential cause of false-negative findings of malignancy on FDG PET scans. When bronchioloalveolar carc inoma is suggested, FDG PET results should be interpreted in combinati on with high-resolution CT findings.