Middle Lobe Syndrome

Epidemiology

  • First described in 1948 by Graham
  • One family had syndrome in 4/5 members

Physiology

  • RML bronchus narrowing or angulation (may be worsened by presence of enlarged lymph nodes in TB) with distal atelectasis or recurrent pneumonia
  • Fish-mouth shape with long course (as well as poor collateral ventilation to RML) may predispose bronchus collapse in some patients
  • Some cases are associated with tenacious secretions (seen in Sjogren’s syndrome, etc.)

Diagnosis

  • FOB: RML bronchus usually appears normal in these patients
  • CXR/Chest CT Patterns: RML atelectasis, infiltrate, or bronchiectasis

Clinical

(usually asymptomatic)

  • Bronchiectasis of RML (see [[Bronchiectasis]])

References

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