Follicular Bronchiolitis

(aka Pulmonary Lymphoid Hyperplasia)

Etiology

  • Primary Pulmonary Lymphoid Hyperplasia
  • Secondary Pulmonary Lymphoid Hyperplasia
    • Sjogren’s Syndrome (see [[Sjogrens Syndrome]])
    • Rheumatoid Arthritis (see [[Rheumatoid Arthritis]])
    • AIDS (see [[HIV Disease]])
    • Bronchiectasis (see [[Bronchiectasis]])
    • Other Infections

Physiology

  • Infiltration of bronchiolar or bronchial walls by hyperplastic lymhoid follicles with germinal centers (composed of lymphocytes)
  • Represents one of the lymphoproliferative disorders of the lungs (along with LIP, MALTomas, and nodular lymphoid hyperplasia/pseudolymphoma

Pathology

  • Lymphoid Hyperplasia: peribronchiolar germinal centers

Diagnosis

  • PFT’s: obstruction (distinct from LIP, which usually produces restriction)
  • FOB: lymphocytic-predominant BAL (similar to Sarcoid and HP)
  • CXR/Chest CT Pattern
    • Centrilobular Nodules with Peripheral Tree-In-Bud Pattern: characteristic of bronchiolar disease
    • Ground-Glass Opacities:
    • Mediastinal Adenopathy: also seen in LIP and Nodular Lymphoid Hyperplasia

Clinical

  • Centrilobular Nodules + Ground-Glass Infiltrates with Obstructive PFT’s (see [[Obstructive Lung Disease]] and [[ILD-Etiology]])
    • Exertional Dyspnea: typically slowly progressive

Treatment

  • Treat Underlying Condition
  • Steroids: effective

References

  • xxx