Chest Radiology: Upper Lobe Predominant Lung Diseases
Review of chest radiology upper lobe predominant lung diseases for radiology and nuclear medicine board examinations.
Chest Radiology: Upper Lobe Predominant Lung Diseases
Upper lobe Predominant
1) Pneumoconioses
a) Silicosis
b) Coal Workers Pneumoconiosis
c) Progressive massive fibrosis
d) Berryliosis
e) Inhalation talc pneuomoconiosis
2) Tuberculosis
3) Sarcoidosis
4) Respiratory bronchiolitis-interstitial lung disease (RB-ILD)
5) Caplan syndrome
6) Ankylosing spondylitis
7) Allergic bronchopulmonary aspergillosis (ABPA)
8) Centrilobular emphysema
9) Cystic fibrosis
10) Langerhans Cell Histiocytosis
Lower Lobe predominant
1) Usual Interstitial Pneumonia (UIP)
2) Nonspecific Interstitial Pneumonia (NSIP)
3) Desquamative interstitial pneumonia (DIP)
4) Scleroderma
5) Rheumatoid arthritis (exception is Caplan syndrome)
6) Secondary emphysema from alpha-1 antitrypsin deficiency
7) Asbestosis (the only common inhalational disease that is lower lobe predominant)
8) Lymphocytic interstitial pneumonia (LIP)
9) Cryptogenic organizing pneumonia (COP)
10) Primary ciliary dyskinesia
Diffuse, Central, RML/lingula, and/or Randomly Distributed
1) Granulomatosis with polyangiitis (Wegener’s granulomatosis)
2) Goodpasture syndrome
3) Eosinophilic granulomatosis with polyangiitis (prior Churg-Strauss)
4) Hypersensitivity pneumonitis (hard to classify but can have findings in various areas of lung)
5) Pneumocystis jiroveci pneumonia (PJP) *also hard to classify
6) Pulmonary amyloidosis
7) Lymphangioleiomyomatosis
8) Acute interstitial pneumonia/ARDS
9) Miliary tuberculosis
10) Pulmonary alveolar proteinosis
11) Pulmonary edema
12) Mycobacterium avium complex (MAC)
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Upper Lobe Predominant:
Silicosis: Upper lobe predominant perilymphatic nodules which may be calcified and hilar nodes with eggshell calcifications. Look for history of working in a mine or other industrial exposure. May progress to progressive massive fibrosis with large upper lobe masses with radiating strands. If see cavitation must rule out silicotuberculosis given higher risk of TB when silicosis is present.
Coal Workers Pneumoconiosis: Like appearance of silicosis including higher risk of
developing TB, risk of progressing to progressive massive fibrosis.
Progressive massive fibrosis: I think of this as end stage silicosis/coal workers pneumoconiosis. Upper lobe predominant masses. May also be seen with other processes such as inhalational talc pneumoconiosis. PMF is often T2 dark on MRI vs cancer that is often T2 bright. I’m not sure how many of these patients really get an MRI or if the T2 dark finding has good enough diagnostic performance to avoid tissue sampling but you should know this for the board exam.
Berryliosis: Results from inhalation of metal particles used in aircraft and other industries. Results in upper lobe predominant granulomatous disease and fibrosis including hilar adenopathy and reticular opacities. Bronchoalveolar lavage can be helpful for diagnosis.
Inhalational talc pneumoconiosis/talk-induced lung disease: Be aware that some consider “pulmonary talcosis” to denote the IV injection of talc (filler in tablets such as pain pills that are crushed and injected for IV drug use) which ends up embolized in the pulmonary arteries. So, to be specific for lung disease use the other terms specified in bold. For inhalational talc pneumoconiosis search for hyperdense micronodules in upper lobe predominant distribution that can conglomerate into masses much like progressive massive fibrosis. This inhalation classically happens from occupational exposure rather than drug abuse, look for a history of a rubber factory worker. This is also different from talc pleurodesis, but you should be familiar with that
as well (intentional talc injection into pleural space to prevent/reduce recurrent pleural
effusion/pneumothorax--look for pleural thickening and pleural calcification due to talc).
Tuberculosis: Any cavitation in setting of silicosis/coal workers pneumoconiosis is assumed to be TB until proven otherwise. Is upper lobe predominant in chronic form with exception of miliary TB which is bilateral and diffuse micronodularity. If you see upper lobe tree-in-bud opacities with cavitation, think TB first. May also see upper lobe patchy consolidation/nodularity. Get bronchoalveolar lavage for diagnosis. If you see upper lobe fibrosis, consider old TB, progressive pulmonary fibrosis, sarcoidosis. Acute (primary) TB can be opacity anywhere in lung, even presenting with lobar consolidation. Cavitation is much more common in chronic TB. When infection is walled off and forms a caseating granuloma that calcifies, that is your Ghon complex. Look for the right>left mediastinal lymphadenopathy for primary TB, especially in kids. Ranke complex: Ghon complex and mediastinal/hilar nodal calcification. Miliary TB means hematogenous spread and has a poor prognosis. TB associated
with increased risk of aspergilloma.
Sarcoidosis: This can look like just about anything anywhere in the body. Almost all patients with sarcoidosis will show lung changes. Classic findings are symmetric mediastinal and hilar lymphadenopathy, micronodularity, other lung opacities,
pleural effusions, less common with masses and cavitation. Late-stage sarcoidosis may show fibrosis/honeycombing/bronchiectasis. Note that nodules and fibrosis are most common in upper lung zones.
Respiratory bronchiolitis-interstitial lung disease (RB-ILD): Smoking related. On spectrum with desquamative interstitial pneumonia (DIP)--these are the same disease. RB-ILD is slightly upper lobe predominant, and DIP is lower lobe predominant. RB-ILD has apical centrilobular ground glass nodules. DIP is basilar predominant ground glass opacities with small cysts often in subpleural location. RB-ILD is early change and DIP is late stage. RB-ILD is indistinguishable on imaging from acute hypersensitivity pneumonitis so during board exams look for the smoking history to confirm RB-ILD.
Caplan syndrome / rheumatoid pneumoconiosis: Pulmonary fibrosis in setting of
rheumatoid arthritis. Upper lobe predominant nodules. This is essentially pneumoconiosis from various cases in patient with rheumatoid arthritis.
Ankylosing spondylitis: Pulmonary presentation includes upper lobe fibrosis and bullae. May start unilateral and then become bilateral. Additional manifestations of ankylosing spondylitis are highly tested and are beyond the scope of this pulmonary review but should be carefully studied.
Allergic bronchopulmonary aspergillosis (ABPA): Upper lobe predominant endobronchial lesion. Look for hyperdense material (calcified mucoid impaction) within dilated upper lobe bronchi, the “finger in glove sign”. Look for history of asthma and eosinophilia. As per name, this is an allergic phenomenon and not an infection. Less common in patients with cystic fibrosis. Mild cases may only need corticosteroids, antifungals may also be used. If immunocompromised may develop angioinvasive aspergillosis including if on long-time high dose steroids. This can be dangerous and may have associated hemoptysis, and on imaging may show a halo around a nodule due to hemorrhage or atoll/reversed halo sign which is central ground glass opacity surrounded by denser consolidation. May see wedge-like consolidation from pulmonary infarction and direct invasion into chest wall. Note reverse halo sign is more classic for cryptogenic organizing pneumonia but may also be seen with invasive fungal infections and other entities (TB, sarcoid, etc.).
Centrilobular emphysema: Smoking related. Look for evenly distributed areas of absent lung (low attenuation) in upper lobes. Small pulmonary vessels.
Cystic fibrosis: Upper lobe bronchiectasis with recurrent infections. Really if they give you history of recurrent infection and show upper lobe bronchiectasis it is CF. Bronchiectasis in order of increasing size is cylindrical, varicoid and cystic. CF has cystic bronchiectasis. May see air-fluid levels, asymmetric consolidation. Cause is too little chloride removal due to genetic abnormality resulting in thick secretions. May see air trapping/mosaic attenuation and finger in glove sign from mucous impaction. (Finger in glove with recurrent infection is CF, finger in glove with asthma/eosinophilia is ABPA). Highly tested and make sure to review the other non-pulmonary manifestations of CF.
Pulmonary Langerhans Cell Histiocytosis (LCH): Nodules and irregular/bizarre cysts in upper lobe predominant distribution sparing the extreme lung bases/costophrenic sulci. Late disease may have fibrosis/honeycombing. Associated with smoking in young adults (by far most common) or a manifestation of disseminated LCH and these are distinct processes with same imaging appearance. LCH is upper lobe predominant, lymphocytic interstitial pneumonia (LIP) is lower lobe predominant, lymphangioleiomyomatosis (LAM) is all over. Treatment is smoking cessation (if smoking related) and/or corticosteroids. If severe may need lung transplant.
