Foreign Body Aspiration Mimicking an Endobronchial Neoplasm: A Case Report and Review of the Literature.

Foreign body aspiration (FBA) is infrequently encountered in the adult population, with major risk factors including advancing age, intoxication, and disorders of the central nervous system. Here, we present a case of FBA in an adult undergoing routine lung cancer screening to review imaging findings and highlight potential pitfalls for the practicing radiologist. A low-dose chest computed tomography (CT) scan was performed for lung cancer screening in a 57-year-old male with a one-month history of worsening dyspnea and cough. An endobronchial lesion was identified in the right bronchus intermedius. A follow-up 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) revealed hypermetabolic activity in the region of interest, raising concern for malignancy. Bronchoscopy was performed, revealing a nodular mass adjacent to a foreign body in the bronchus intermedius. Histopathologic analysis of the tissue sample revealed the presence of an aspirated foreign body with squamous metaplasia of the respiratory epithelium. Adult FBA is an uncommon clinical entity that may be incidentally observed on a screening chest CT. Relevant multimodality imaging findings are discussed here, along with a review of the accompanying pathologic changes seen with chronic airway impaction.