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False-Positive FDG-PET and Bronchial Anthracofibrosis

  • Mi-Ae Kim
    Affiliations
    Division of Pulmonary and Critical Care Medicine, College of Medicine University of Ulsan, Seoul, Republic of Korea
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  • Jae Cheol Lee
    Affiliations
    Division of Oncology, Department of Internal Medicine, Asan Medical Center, College of Medicine University of Ulsan, Seoul, Republic of Korea
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  • Changmin Choi
    Correspondence
    Address for correspondence: Changmin Choi, MD, PhD, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Pungnap 2-dong, Songpa-gu, Seoul, Republic of Korea 138–736
    Affiliations
    Division of Pulmonary and Critical Care Medicine, College of Medicine University of Ulsan, Seoul, Republic of Korea

    Division of Oncology, Department of Internal Medicine, Asan Medical Center, College of Medicine University of Ulsan, Seoul, Republic of Korea
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      A 73-year-old woman presented to our departmentwith a cough for 2 months. She was a housewife and had no history of smoking or tuberculosis, but she did have a history of significant exposure to biomass because she burned firewood. Chest radiograph and chest computed tomography showed a 2.5-cm–sized lung nodule at the left upper lung and percutaneous needle biopsy was performed. Pathologic findings suggested a pulmonary adenocarcinoma. 2-[18F] fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) scan showed an enlarged 1.3-cm–sized 4R LN (right lower paratracheal lymph node) with 4.9 standardized uptake value (Fig. 1A). endobronchial ultrasound-guided transbronchial needle aspiration was performed at 4R LN for a mediastinal staging. Bronchial anthracofibrosis was observed during bronchoscopy, (Fig. 1B) and pigmentation of the aspirated material was observed macroscopically during endobronchial ultrasound-guided transbronchial needle aspiration. Left upper lobectomy was performed, and 4R LN was confirmed as a reactive LN with anthracosis on the resected lung specimen.
      Figure thumbnail gr1
      Figure 1A, FDG-positive emission tomography scan showing enlarged 4R LN with positive uptake. B, Bronchial anthracofibrosis of right upper lobar bronchus during bronchoscopy.
      Bronchial anthracofibrosis (BAF) is a bronchoscopically visible anthracotic pigmentation associated with the narrowing or obliteration of the bronchi. BAF was previously thought to be associated with active or old tuberculosis infection, but it is now believed to be associated with chronic biomass-fuel smoke exposure.
      • Gupta A
      • Shah A
      Bronchial anthracofibrosis: an emerging pulmonary disease due to biomass fuel exposure.
      Mediastinal lymphadenopathy with calcification is common in BAF.
      • Gupta A
      • Shah A
      Bronchial anthracofibrosis: an emerging pulmonary disease due to biomass fuel exposure.
      False-positive PET with FDG as a tracer uptake in anthracosis often mimics metastatic lymphadenopathy seen in lung cancer.
      • Kim YK
      • Lee KS
      • Kim BT
      • et al.
      Mediastinal nodal staging of nonsmall cell lung cancer using integrated 18F-FDG PET/CT in a tuberculosis-endemic country: diagnostic efficacy in 674 patients.
      In conclusion, if BAF is found on bronchoscopy, PET scans tend to be a false-positive because of anthracosis.

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