CT OF CHRONIC INFILTRATIVE LUNG-DISEASE - PREVALENCE OF MEDIASTINAL LYMPHADENOPATHY

Objective: Our goal was to determine the prevalence of mediastinal lym ph node enlargement at CT in patients with diffuse infiltrative lung d isease. Materials and Methods: The study was retrospective and include d 175 consecutive patients with diffuse infiltrative lung diseases. Di agnoses included idiopathic pulmonary fibrosis (IPF) (n = 61), usual i nterstitial pneumonia associated with collagen vascular disease (CVD) (n = 20), idiopathic bronchiolitis obliterans organizing pneumonia (PO OP) (n = 22), extrinsic allergic alveolitis (EAA) (n = 17), and sarcoi dosis (n = 55). Fifty-eight age-matched patients with CT of the chest performed for unrelated conditions served as controls. The presence, n umber, and sites of enlarged nodes (short axis greater than or equal t o 10 mm in diameter) were recorded. Results: Enlarged mediastinal node s were present in 118 of 175 patients (67%) with infiltrative lung dis ease and 3 of 58 controls (5%) (p < 0.001). The prevalence of enlarged nodes was 84% (46 of 55) in sarcoidosis, 67% (41 of 61) in IPF, 70% ( 14 of 20) in CVD, 53% (9 of 17) in EAA, and 36% (8 of 22) in POOP. The mean number of enlarged nodes was higher in sarcoidosis (mean 3.2) th an in the other infiltrative diseases (mean 1.2) (p < 0.001). Enlarged nodes were most commonly present in station 10R, followed by 7, 4R, a nd 5. Conclusion: Patients with infiltrative lung disease frequently h ave enlarged mediastinal lymph nodes. However, in diseases other than sarcoid, usually only one or two nodes are enlarged and their maximal short axis diameter is < 15 mm.