Sjögren syndrome (thoracic manifestations)

Thoracic manifestations of Sjögren syndrome are common and sometimes detected before the syndrome diagnosis. Thoracic / lung/lung involvement many occur in ∼9–20% of patients ⁴. 

For a broad discussion on the syndrome and its typical lymphocytic infiltration of the exocrine glands, please refer to the main article on Sjögren syndrome. 

Clinical presentation

Patients usually present with chronic dry cough and dyspnoea.

Pathology

Several pathological entities can arise which include 

• interstitial lung changes
• airway abnormalities
• cysts
• sequelae of recurrent infection
• associated malignancies / lymphoproliferative/lymphoproliferative conditions

Pathogenesis of the pulmonary involvement in patients with Sjögren syndrome is not clearly understood. Studies have shown an important role of epithelial cells and B-cell hyperactivation as part of the mechanism of this involvement ¹. 

Pulmonary histologic features are diverse and different patterns of interstitial pneumonia or airway abnormalities are commonly seen in the same patient. 

Radiographic features

CT

• airway abnormalities:
  • bronchitis/bronchiolitis
    • bronchiectasis or bronchiolectasis
    • bronchial wall thickening
  • centrilobular nodules and tree-in-bud
    • mosaic attenuation (inferring obstructive bronchiolitis)
• interstitial pneumonia
  • nonspecific interstitial pneumonia (NSIP) is the most common pattern associated with Sjögren syndrome ¹
    • areas of ground-glass attenuation
    • septal thickening
    • traction bronchiectasis
    • lung volume loss
  • cryptogenic organising pneumonia (COP)
  • usual interstitial pneumonia (UIP)
• lymphoproliferative disorders
  • lymphocytic interstitial pneumonia (LIP): can either be grouped under the umbrella of interstitial pneumonia or lymphoproliferative disorders
    • ground-glass attenuation
    • air cysts
    • septal thickening
    • thickening of the peribronchovascular interstitium
    • centrilobular or subpleural nodules
  • diffuse lymphoid hyperplasia
    • similar to LIP but with a more interstitial than alveolar involvement
    • interlobular septal thickening
    • peribronchovascular interstitium thickening
  • mucosa-associated lymphoid tissue (MALT) lymphoma: the most common malignancy in patients with primary Sjögren syndrome
    • solitary or multiple nodules/masses along bronchovascular bundles ¹
    • areas of consolidation or ground-glass attenuation
  • amyloid lung deposition
    • it has been reported to occur in multiple organs other than the lungs
    • multiple nodules that may calcify
    • cystis
    • septal thickening
• mediastinal manifestations
  • lymphadenopathy
  • thymic lymphoid hyperplasia
  • multilocular thymic cysts

Differential diagnosis

For the lung lymphoproliferative disorders, considerations should include: 

• sarcoidosis
• lymphangitic carcinomatosis
• secondary lymphoma from other organs
• cryptogenic organising pneumonia