Adenocarcinoma of lung includes the subtype bronchioloalveolar cell carcinoma (BAC). SUVs have been shown to be significantly lower in adenocarcinoma then in other types of non-small cell lung carcinoma (NSCLC), including squamous cell and large cell carcinoma. SUVs have further been found to be significantly lower in BAC compared to other adenocarcinoma and other NSCLC types, with SUVs lowest in BAC, followed by other adenocarcinoma. FDG-PET/CT has also been found useful in distinguishing BAC from adeno+BAC, with pure BAC exhibiting smaller size, lower tumour density and lower FDG uptake.
Such findings suggest that FDG uptake may be related to different tumour cell subtypes expressing variable glycolytic activities, rather than poorer differentiation of the tumour. Low FDG uptake in a morphologically suspicious area in the lung is therefore an important false negative in the FDG-PET/CT assessment for lung cancer.