Follicular Bronchiolitis / Bronchitis

Definition

Reactive lymphoid follicles localized to peribronchiolar and peribronchial tissues

Clinical
- Gradual onset of dyspnea, cough
- May occur at any age
- Frequently associated with immune related diseases
  - Autoimmune diseases including collagen vascular
  - Immunodeficiency including AIDS and common variable immunodeficiency
- May have hyper or hypogammaglobulinemia gammopathy
- Most respond to steroids
High resolution computed tomography (HRCT)
- Centrilobular and occasionally peribronchial nodules
Histopathologic features
- Scattered reactive lymphoid follicles around bronchioles and bronchi
  - Lymphoid nodules may be >1 mm diameter
  - May compress bronchiole lumens
    - Acute exudate may be seen in lumens
    - Distal changes of obstructive pneumonia may be seen
  - Occasional cases may also have a lymphangitic pattern involving septa and pleura
- Mild infiltrate may extend into adjacent alveolar septa
  - Occasional cases may have a more substantial interstitial infiltrate and overlap with lymphocytic interstitial pneumonitis
- Mixed polytypic B and T cells

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