Progressive massive fibrosis
Progressive massive fibrosis (PMF) refers to the formation of large mass-like conglomerates, predominantly in the upper pulmonary lobes, associated with radiating strands. These classically develop in the context of certain pneumoconioses (especially coal worker's pneumoconiosis and silicosis) although similar mass-like densities have occasionally been described with talcosis.
Radiographic features
Plain radiograph
May be seen as large symmetric bilateral opacities with irregular margins in the upper lobes 3.
CT
Mass-like areas of lung opacification associated with radiating strands are seen; the "sausage-shaped" mass is characteristic. These regions commonly contain air bronchograms and calcifications 4. These areas can shrink over time and migrate towards the hilar regions 5.
MRI
Magnetic resonance imaging can be helpful for distinguishing between progressive massive fibrosis and lung cancer 3. The latter typically appears as T2-bright, whereas progressive massive fibrosis appears as T2-dark (compared to skeletal muscle) 3.
The most frequent MRI appearance are regions which have following signal characteristics 1,2:
- T1: iso- to hyperintense
-
T2:
- hypointense (compared with skeletal muscle)
- areas of internal high T2 signal
- there may be rim enhancement
Nuclear medicine
On PET-CT, progressive massive fibrosis can be FDG-avid 3.
Differential diagnosis
Possible differential considerations include:
- pulmonary talc granulomatosis
- sarcoidosis
- lung cancer: has a higher SUVmax on PET-CT 7
In some situations consider pulmonary manifestations of sarcoidosis.
Related Radiopaedia articles
Chest
- imaging techniques
-
chest x-ray
-
approach
- adult
- pediatric
- neonatal
-
airspace opacification
- differential diagnoses of airspace opacification
- lobar consolidation
-
atelectasis
- mechanism-based
- morphology-based
- lobar lung collapse
- chest x-ray in the exam setting
- cardiomediastinal contour
- chest radiograph zones
- tracheal air column
- fissures
- normal chest x-ray appearance of the diaphragm
- nipple shadow
-
lines and stripes
- anterior junction line
- posterior junction line
- right paratracheal stripe
- left paratracheal stripe
- posterior tracheal stripe/tracheo-esophageal stripe
- posterior wall of bronchus intermedius
- right paraspinal line
- left paraspinal line
- aortic-pulmonary stripe
- aortopulmonary window
- azygo-esophageal recess
- spaces
- signs
- air bronchogram
- big rib sign
- Chang sign
- Chen sign
- coin lesion
- continuous diaphragm sign
- dense hilum sign
- double contour sign
- egg-on-a-string sign
- extrapleural sign
- finger in glove sign
- flat waist sign
- Fleischner sign
- ginkgo leaf sign
- Golden S sign
- Hampton hump
- haystack sign
- hilum convergence sign
- hilum overlay sign
- Hoffman-Rigler sign
- holly leaf sign
- incomplete border sign
- juxtaphrenic peak sign
- Kirklin sign
- medial stripe sign
- melting ice cube sign
- more black sign
- Naclerio V sign
- Palla sign
- pericardial fat tag sign
- Shmoo sign
- silhouette sign
- snowman sign
- spinnaker sign
- steeple sign
- straight left heart border sign
- third mogul sign
- tram-track sign
- walking man sign
- water bottle sign
- wave sign
- Westermark sign
-
approach
- HRCT
-
chest x-ray
- airways
- bronchitis
- small airways disease
-
bronchiectasis
- broncho-arterial ratio
- related conditions
- differentials by distribution
- narrowing
-
tracheal stenosis
- diffuse tracheal narrowing (differential)
-
bronchial stenosis
- diffuse airway narrowing (differential)
-
tracheal stenosis
- diverticula
- pulmonary edema
-
interstitial lung disease (ILD)
- drug-induced interstitial lung disease
-
hypersensitivity pneumonitis
- acute hypersensitivity pneumonitis
- subacute hypersensitivity pneumonitis
- chronic hypersensitivity pneumonitis
- etiology
- bird fancier's lung: pigeon fancier's lung
- farmer's lung
- cheese workers' lung
- bagassosis
- mushroom worker’s lung
- malt worker’s lung
- maple bark disease
- hot tub lung
- wine maker’s lung
- woodsman’s disease
- thatched roof lung
- tobacco grower’s lung
- potato riddler’s lung
- summer-type pneumonitis
- dry rot lung
- machine operator’s lung
- humidifier lung
- shower curtain disease
- furrier’s lung
- miller’s lung
- lycoperdonosis
- saxophone lung
-
idiopathic interstitial pneumonia (mnemonic)
- acute interstitial pneumonia (AIP)
- cryptogenic organizing pneumonia (COP)
- desquamative interstitial pneumonia (DIP)
- non-specific interstitial pneumonia (NSIP)
- idiopathic pleuroparenchymal fibroelastosis
- lymphoid interstitial pneumonia (LIP)
- respiratory bronchiolitis–associated interstitial lung disease (RB-ILD)
- usual interstitial pneumonia / idiopathic pulmonary fibrosis (UIP/IPF)
-
pneumoconioses
- fibrotic
- non-fibrotic
-
lung cancer
-
non-small-cell lung cancer
-
adenocarcinoma
- pre-invasive tumors
- minimally invasive tumors
- invasive tumors
- variants of invasive carcinoma
- described imaging features
- adenosquamous carcinoma
- large cell carcinoma
- primary sarcomatoid carcinoma of the lung
- squamous cell carcinoma
- salivary gland-type tumors
-
adenocarcinoma
- pulmonary neuroendocrine tumors
- preinvasive lesions
-
lung cancer invasion patterns
- tumor spread through air spaces (STAS)
- presence of non-lepidic patterns such as acinar, papillary, solid, or micropapillary
- myofibroblastic stroma associated with invasive tumor cells
- pleural invasion
- vascular invasion
- tumors by location
- benign neoplasms
- pulmonary metastases
- lung cancer screening
- lung cancer staging
-
non-small-cell lung cancer