Objective: The aim of our study was to describe 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) findings of a localized form of bronchioloalveolar carcinoma and to compare those findings with other cell types of lung cancer.
Subjects and methods: FDG PET was performed in 48 patients with lung cancer. The patients had carcinomas of various cell types: bronchioloalveolar carcinoma (n = 9), squamous cell carcinoma (n = 11), adenocarcinoma (n = 22), and other cell types (n = 6). Using FDG PET, we compared peak standardized uptake values among the various cell types of lung cancer. CT and pathologic findings for patients with bronchioloalveolar carcinoma were also reviewed.
Results: Overall, 48 malignant tumors showed a mean peak standardized uptake 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 standardized uptake value for bronchioloalveolar carcinoma was significantly lower than that for adenocarcinoma and squamous cell carcinoma (p < .001). On high-resolution CT scans, bronchioloalveolar carcinomas appeared 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 well differentiated, having moderate degrees of nuclear atypism, mild degrees of mitotic figure, desmoplasia, and necrosis.
Conclusion: The localized form of bronchioloalveolar carcinoma shows significantly lower peak standardized uptake values than do other lung carcinomas. Thus, bronchioloalveolar carcinoma can be a potential cause of false-negative findings of malignancy on FDG PET scans. When bronchioloalveolar carcinoma is suggested, FDG PET results should be interpreted in combination with high-resolution CT findings.