Not All PET-Avid Endobronchial Lesions Are Malignant: A Case of Chronic Foreign Body Aspiration

Background: Low-dose CT scanning is a key tool in lung cancer screening, enabling the detection of clinically significant abnormalities in asymptomatic individuals and often prompting further diagnostic evaluation. Case Presentation: We describe the case of an 80-year-old man with a heavy smoking history who was found to have a new right middle lobe collapse on screening CT. Subsequent positron emission tomography-computed tomography (PET/CT) imaging demonstrated mild fluorodeoxyglucose (FDG) uptake (SUVmax 2.7), raising concern for a low-grade endobronchial malignancy versus mucoid impaction. Flexible fiberoptic bronchoscopy revealed a large exophytic endobronchial mass occluding the airway. Histopathologic examination of the biopsy sample unexpectedly revealed vegetable material, consistent with chronic foreign-body aspiration. Discussion: Unrecognized aspiration events are relatively common in elderly adults and can mimic malignancy on imaging. This case highlights an important diagnostic pitfall: inflammatory endobronchial processes, including foreign-body granulomas, can demonstrate FDG uptake and mimic malignancy. Conclusion: Clinicians should maintain a broad differential diagnosis when evaluating PET-avid endobronchial lesions, especially in elderly patients.