Diffuse Pulmonary Ossification (DPO)

Epidemiology

  • History: Luschka first described DPO in 1856

Etiology

Cardiac Disease

  • Chronic Congestive Heart Failure (CHF) (see Congestive Heart Failure, [[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, [[xxxx]])
    • Epidemiology: has been associated with the nodular form of disease
  • Mitral Stenosis (see Mitral Stenosis, [[Mitral Stenosis]])
    • Epidemiology: has been associated with the nodular form of disease

Other

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

Physiology

  • 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

Diagnosis

Serum Chemistry

  • Normal Serum Calcium
  • Normal Serum Phosphate

Serum Alkaline Phosphatase (see Serum Alkaline Phosphatase, [[Serum Alkaline Phosphatase]])

  • Normal

High-Resolution Chest CT (HRCT) (see High-Resolution Chest Computed Tomography, [[High-Resolution Chest Computed Tomography]])

  • 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

Bone Scan (see Bone Scan, [[Bone Scan]])

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

Bronchoscopy (see Bronchoscopy, [[Bronchoscopy]])

  • Transbronchial Biopsy: may be diagnostic

Pulmonary Function Tests (PFT’s) (see Pulmonary Function Tests, [[Pulmonary Function Tests]])

  • Restriction with Decreased DLCO: observed in extensive disease

Video-Assisted Thoracoscopy (VATS) with Lung Biopsy (see Video-Assisted Thoracoscopic Surgery, [[Video-Assisted Thoracoscopic Surgery]])

  • 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)

Clinical Manifestations

General Comments

  • Disease Course: indolent or slowly progressive

Pulmonary Manifestations

Pulmonary Calcifications

  • xxxx

Treatment

Therapies without Clinical Efficacy

  • Bisphosphonates (see Bisphosphonates, [[Bisphosphonates]])
  • Calcium-Binding Agents
  • Corticosteroids (see Corticosteroids, [[Corticosteroids]])
  • Coumadin (see Coumadin, [[Coumadin]])
    • Pharmacology: inhibition of osteocalcin
  • Low Calcium Diet

References

  • 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]