Table 1.
Pathologic patterns and agents of pulmonary infection
| Pattern | Most Common Agents |
|---|---|
| Airway disease | |
| Bronchitis/bronchiolitis | Virus; bacteria; mycoplasma |
| Bronchiectasis | Bacteria; mycobacteria |
| Acute exudative pneumonia | |
| Purulent (neutrophilic) | Bacteria |
| Lobular (bronchopneumonia) | Bacteria |
| Confluent (lobar pneumonia) | Bacteria |
| With granules | Botryomycosis; actinomycosis |
| Eosinophilic | Parasites |
| Foamy alveolar cast | Pneumocystis |
| Acute diffuse/localized alveolar damage | Virus; polymicrobial |
| Chronic pneumonia | |
| Fibroinflammatory | Bacteria |
| Organizing diffuse/Localized alveolar damage | Virus |
| Eosinophilic | Parasite |
| Histiocytic | Mycobacteria |
| Interstitial pneumonia | |
| Perivascular lymphoid | Virus; atypical agents |
| Eosinophilic | Parasite |
| Granulomatous | Mycobacteria |
| Nodules | |
| Large | |
| Necrotizing | Fungi; mycobacteria |
| Granulomatous | Fungi; mycobacteria |
| Fibrocaseous | Fungi; mycobacteria |
| Calcified | Fungi; mycobacteria |
| Miliary | |
| Necrotizing | Viral; mycobacteria; fungi |
| Granulomatous | Fungi |
| Cavities and cysts | Fungi; mycobacteria |
| Intravascular/Infarct | Fungi |
| Spindle cell pseudotumor | Mycobacteria |
| Minimal “Id”type reaction | Polymicrobial |
From Jaroszewski DE, Viggiano RW, Leslie KO. Optimal processing of diagnostic lung specimens. In: Leslie KO, Wick MR, editors. Practical pulmonary pathology: a diagnostic approach, 2nd edition. Philadelphia: Elsevier/Saunders; 2011. (Pattern Recognition Series). p. 15–25; with permission.