Lung cancer - groundglass opacity (GGO) progressing to mass over 7 years
Presentation
Incidental finding on a chest radiograph 7 years ago. Now cough for 3 weeks. Smoker.
Patient Data
different in a 7-year period
Paired images from 7-years-ago and today: Small ground glass opacity in the left apical segment of lower lobe. Note no distortion of vessels or solid component. Progression in 7 years to a solid, spiculated mass with extension to the pleura and central cavitation.
18FDG-PET/CT
No FDG accumulation in the left apical segment of lower lobe 7-years-ago. Pure ground glass opacities often produce false negative results on FDG PET/CT. As a result, the Fleischner guidelines only recommend FDG PET/CT in the assessment of solid nodules.
Case Discussion
Detection of ground glass opacities is an important component of lung cancer screening. These lesions are thought to be premalignant ie. atypical adenomatous hyperplasia progressing to minimally invasive adenocarcinoma and then invasive malignancy. They can be very slow growing (ie. 7 years in this case) and are usually non-FDG avid. Determination of when to biopsy and/or excise is problematic, and follow-up with imaging is an option. Growth or development of a solid (nodular) component are critical concerning findings.