Acute Fibrinous and Organizing Pneumonia

Definition

• Acute onset lung disease characterized by balls of fibrin filling alveoli

Alternate/Historical Names

• AFOP

Diagnostic Criteria

• Shares acute/subacute onset of symptoms with AIP/DAD
  • Age of onset 33-78
• Patchy involvement rather than diffuse
  • Intervening lung is normal
• Alveoli are filled with balls of fibrin
  • No hyaline membranes
• Organization present in all cases
• Mild to moderate interstitial lympho-plasmacytic interstitial infiltrate
• Reactive pneumocyte hyperplasia
• Vascular thrombi in some cases
• Rapid progression in about half of patients with resultant death, similar to AIP
• Has been proposed as a variant of AIP/DAD
• Only one series (Beasley 2002) and a few case reports

Gerald J Berry MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Classification / Lists

Smoking Related Lung Diseases

• Carcinoma
• Emphysema
• Chronic bronchitis
• Respiratory bronchiolitis associated interstitial lung disease
• Desquamative interstitial pneumonia
• Langerhans cell histiocytosis (histiocytosis X)
• Usual interstitial pneumonia (idiopathic pulmonary fibrosis)

Idiopathic Interstitial Lung Diseases

• Acute interstitial pneumonia (diffuse alveolar damage)
• Acute fibrinous and organizng pneumonia
• Cryptogenic organizing pneumonia (BOOP)
• Desquamative interstitial pneumonia
• Lymphocytic interstitial pneumonitis
• Nonspecific interstitial pneumonia
• Respiratory bronchiolitis associated interstitial lung disease
• Usual interstitial pneumonia (idiopathic pulmonary fibrosis)

Other Diffuse Parenchymal Lung Diseases

• Alveolar microlithiasis
• Alveolar proteinosis
• Eosinophilic pneumonia, acute
• Eosinophilic pneumonia, chronic
• Eosinophilic pneumonia, simple
• Follicular broncholitis/bronchitis
• Hypersensitivity pneumonitis
• Langerhans cell histiocytosis (histiocytosis X)
• Lymphangioleiomyomatosis
• Pneumoconioses
• Sarcoidosis
• Secondary to other known causes
  • Collagen vascular disease
  • Drug reactions
  • Lymphangitic carcinoma

Bibliography

• Beasley MB, Franks TJ, Galvin JR, Gochuico B, Travis WD. Acute fibrinous and organizing pneumonia: a histological pattern of lung injury and possible variant  of diffuse alveolar damage. Arch Pathol Lab Med. 2002 Sep;126(9):1064-70.