Diffuse Pulmonary Ossification (DPO)

Epidemiology

Chronic Congestive Heart Failure (CHF) (see Congestive Heart Failure)
- Epidemiology: has been associated with the nodular form of disease
- Physiology: passive congestion results in extravasation of red blood cells with deposition of hemosiderin into alveolar walls -> inflammation, fibrosis, and hyalinization
Hypertrophic Subaortic Stenosis (see xxxx)
- Epidemiology: has been associated with the nodular form of disease
Mitral Stenosis (see Mitral Stenosis)
- Epidemiology: has been associated with the nodular form of disease

Acute Respiratory Distress Syndrome (ARDS) (see Acute Respiratory Distress Syndrome)
- Epidemiology: has been associated with the dendriform type of disease
Asbestosis (see Asbestos)
- Epidemiology: has been associated with the dendriform type of disease
Chronic Obstructive Pulmonary Disease (COPD) (see Chronic Obstructive Pulmonary Disease
- Epidemiology: has been associated with the dendriform type of disease
Diabetes Mellitus (see Diabetes Mellitus)
- Epidemiology: unclear if diabetes mellitus is a risk factor
Diffuse Alveolar Hemorrhage (DAH) (see Diffuse Alveolar Hemorrhage)
Heavy Metal Exposure (see xxxx)
- Epidemiology: has been associated with the dendriform type of disease
Idiopathic Pulmonary Fibrosis (IPF) (see Idiopathic Pulmonary Fibrosis)
- Epidemiology: has been associated with the dendriform type of disease
Organizing Pneumonia (see Cryptogenic Organizing Pneumonia
- Epidemiology: has been associated with the dendriform type of disease
Rare Earth Pneumoconiosis (see xxxx, [[xxxx]])
- Epidemiology: has been associated with the dendriform type of disease
Recurrent Aspiration Pneumonia (see Aspiration Pneumonia)
Solid Organ Transplant

Heterotopic Bone Formation within the Pulmonary Tissue
- Potential Contributing Factors
  - Cellular and Tissue Injury
  - Alkaline Environment: causes precipitation of calcium salts
  - Cessation of Pulmonary Blood Flow
  - Collagen and Pro-Fibrogenic Cytokines
  - Extravasation
  - Metallic Deposition
Pathologic Subtypes: however, both types may occur in the same patient
- Dendriform: interstitial branching spicules of bone and marrow elements that may protrude into alveoli
  - Usually Invisible on Chest X-Ray
- Nodular Form: intraalveolar bone deposits usually without marrow elements

Findings
- Coral-Like Dendritic Ossification Pattern in Peripheral, Basilar Regions of Lung: in dendriform type
- Diffuse Interlobular and Intralobular Interstitial Thickening
- Smooth Contoured Lobulated Nodules: in nodular type

Less Sensitive in Patients with Milder Forms of Disease
Technique: 99m technetium-methylene diphosphate (99mTc-MDP) bone scintigraphy

Diagnostic
- Dendriform: branching bony spicules appear in the alveolar septa, usually containing fat marrow
- Nodular Form: lobulated bone nodules within the alveolar space (absence of fat or hematopoetic cells)

Luschka H. Ramified ossification of the pulmonary parenchyma. Wirchows Arch 1856; 10:500–505
Extensive diffuse pulmonary ossification. Chest. 1992 Nov;102(5):1614-5 [MEDLINE]
[Diffuse pulmonary ossification associated with idiopathic pulmonary fibrosis]. Arch Bronconeumol. 2004 Dec;40(12):595-8 [MEDLINE]
Idiopathic diffuse pulmonary ossification. Thorax. 2004 Nov;59(11):1004 [MEDLINE]
Diffuse pulmonary ossification: an unusual interstitial lung disease. Curr Opin Pulm Med. 2008 Sep;14(5):488-92. doi: 10.1097/MCP.0b013e3283043e1b [MEDLINE]
The Rapid Appearance and Disappearance of Dendriform Pulmonary Ossification after Diffuse Alveolar Hemorrhage. Am J Respir Crit Care Med. 2016 Feb 1;193(3):333-4. doi: 10.1164/rccm.201506-1199IM [MEDLINE]