Pneumoconiosis
Definition
Lung disease caused by inhaled mineral dust particles
Diagnostic Criteria
Some of the major types of pneumoconiosis are covered briefly here
For more complete coverage, see Biblilography at left
Coal workers pneumoconiosis (CWP)
Damage caused by inhaled carbon particles
Simple CWP
In its pure form, carbon is essentially non-fibrogenic
Dust macules
0.5-6 mm collection of macrophages
Carbon particles are seen in both macrophages and free in the tissue
Principally located along bronchovascular bundles
No significant fibrosis
Foci of centrilobular emphysema
Forms adjacent to carbon particles
Complicated CWP
Occurs when mixed with silica and/or silicates resulting in fibrotic lesions
Mineral dust airway disease
Haphazard collagen with carbon free and in macrophages
Progressive massive fibrosis
Fibrotic nodule/mass ≥1 cm
May result from fused smaller nodules or diffuse fibrosis
Rheumatoid pneumoconiosis
Must have rheumatoid arthritis or Rh factor
Must have large cavitating nodules
Eosinophilic necrotic debris
Surrounded by fibroblasts, histiocytes, giant cells
Silicosis
Damage caused by inhalation of crystalline silica
Acute silicoproteinosis is very rare
Resembles pulmonary alveolar proteinosis
Chronic silicosis is characterized by fibrotic nodules
Sharply demarcated, hypocellular, hyalinized nodules
Lamellated collagen
Silica shows weakly birefringent needles
Nodules may fuse to produce progressive massive fibrosis
Mixed dust pneumoconiosis
Damage caused by inhalation of mixtures containg silica and silicates
Silica shows weakly birefringent needles
Silicates show strongly birefringent plates
Macules of interstitial macrophages
Mixed dust fibrotic lesions
Stellate lesions of macrophages and varying amounts of collagen
Has been termed "medusa head" because of extension into adjacent interstitium
Silicotic nodules
Progressive massive fibrosis
Forms a spectrum with CWP and silicosis
Silicatosis
Damage caused by inhalation of non-asbestos silicates
Includes talc, kaolin, mica, feldspars
Strongly birefringent plates
Findings similar to those of mixed dust pneumoconiosis
Granulomatous reaction may also be seen
Diffuse interstitial fibrosis may also be seen
May represent fused nodules
May resemble UIP
Asbestosis
Damage caused by inhaled asbestos fibers
Diffuse interstitial fibrosis, usually resembling usual interstitial pneumonia (UIP)
Fewer fibroblastic foci
Associated with pleural plaques
Asbestos bodies
Iron positive beads on a translucent core
Carbon and silicates may also ferruginate, but the core is different
Diagnosis requires ≥2 asbestos bodies per square cm and interstitial fibrosis
Berylliosis
T cell hypersensitivity reaction
Closely resembles sarcoidosis
Well formed granulomas with mild to moderate inflammation
Present along bronchovascular bundles
Diagnosed by history and T cell activation test
Hard metal disease
(giant cell interstitial pneumonia)
Damage caused by inhaled cobalt, usually as hard metal dust
Birefringent black intracellular particles
Patchy filling of air spaces by macrophages and multinucleated giant cells
Giant cells frequently ingest macrophages
Multinucleated alveolar lining cells may be present
If giant cells are rare, resembles DIP
Foci of centrilobular fibrosis and interstitial inflammatory infiltrate
BOOP -like changes may be present
Gerald J Berry MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting/updates: 11/20/10
Classification / Lists
Idiopathic Interstitial Lung Diseases
Other Diffuse Parenchymal Lung Diseases
Bibliography
Travis WD, Colby TV, Koss MN, Rosado-de-Christenson ML, Müller NL, King TE Jr. Non-neoplastic Disorders of the Lower Respiratory Tract, AFIP Atlas of Nontumor Pathology, First Series, Fascicle 2, 2002.
Khalil N, Churg A, Muller N, O'Connor R. Environmental, inhaled and ingested causes of pulmonary fibrosis. Toxicol Pathol. 2007;35(1):86-96.
Honma K, Abraham JL, Chiyotani K, De Vuyst P, Dumortier P, Gibbs AR, Green FH, Hosoda Y, Iwai K, Williams WJ, Kohyama N, Ostiguy G, Roggli VL, Shida H, Taguchi O, Vallyathan V. Proposed criteria for mixed-dust pneumoconiosis: definition, descriptions, and guidelines for pathologic diagnosis and clinical correlation. Hum Pathol. 2004 Dec;35(12):1515-23.
Roggli VL, Gibbs AR, Attanoos R, Churg A, Popper H, Cagle P, Corrin B, Franks TJ, Galateau-Salle F, Galvin J, Hasleton PS, Henderson DW, Honma K. Pathology of asbestosis- An update of the diagnostic criteria: Report of the asbestosis committee of the college of american pathologists and pulmonary pathology society. Arch Pathol Lab Med. 2010 Mar;134(3):462-80.