title: Infected tracheal diverticulum mimicking an aggressive mediastinal lesion on FDG PET/CT: an interesting case with review of the literature.
abstract: The differential diagnosis for intense hypermetabolic mediastinal lesions on positron emission tomography (PET) could benefit from the combined morphological and metabolic information present in a fluorodeoxyglucose (FDG) PET/CT study. We report a case of an infected tracheal diverticulum mimicking an FDG-avid malignancy in a patient with a history of chronic lymphoproliferative disease. We review the literature for a systematic approach in the differential diagnosis of cystic mediastinal lesions. The embryological development of the normal tracheobronchial tree is reviewed, followed by a presentation of various congenital and acquired mediastinal lesions. The characteristic CT findings are described for each lesion and the avidity for FDG on PET is mentioned when references are available. This case emphasises that complicated benign processes should be considered in the differential diagnosis of an FDG-avid mediastinal lesion, even in subgroups of patients with significant risk factors for malignancy.
authors.affiliation: Nuclear Medicine Service, Hopital du Sacre-Coeur de Montreal, Montreal, QC, Canada. mathieu.charest@gmail.com
authors.forename: M
authors.initials: M
authors.lastname: Charest
authors.forename: C
authors.initials: C
authors.lastname: Sirois
authors.forename: Y
authors.initials: Y
authors.lastname: Cartier
authors.forename: J
authors.initials: J
authors.lastname: Rousseau
mesh_terms: D000038:Abscess / Q000150:complications*; D000368:Aged; D003937:Diagnosis, Differential; D004240:Diverticulum / Q000000981:diagnostic imaging* / Q000382:microbiology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging*; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D014133:Tracheal Diseases / Q000000981:diagnostic imaging* / Q000382:microbiology*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18