Incidental nonneoplastic parenchymal findings in patients undergoing lung resection for mass lesions.

The prevalence of incidental nonneoplastic lung disease in patients undergoing resection for mass lesions is unknown. We determined the prevalence and characteristics of parenchymal findings in patients with lung nodules, aiming to increase awareness of findings that could potentially impact patient management. A total of 397 patients with benign or malignant mass lesions with available presurgical chest computed tomography scans resected between January 2001 and July 2015 were included. Retrospective histologic assessment of parenchymal abnormalities in at least 1 section of grossly normal lung was performed for each case by 2 pulmonary pathologists and correlated with original pathology reports, clinical history, and radiologic findings. A total of 233 women and 164 men underwent resections for carcinomas (78%) or benign nodules (22%). One hundred one (25%) patients showed parenchymal abnormalities, including 14 patients with multiple findings. The most common abnormal findings were fibrotic interstitial changes (10%), including usual interstitial pneumonia (1%), followed by granulomatous processes (8%). Other findings included aspiration (4%), intravascular thrombi (2%), Langerhans cell histiocytosis (1.5%), constrictive bronchiolitis (1%), atypical lymphoid infiltrates (1%), and amyloidosis (0.5%). Abnormalities were more likely to have been documented in the original pathology report by pulmonary pathologists (68%) than by general pathologists (15%) (P < .0001). Cases with histologic parenchymal abnormalities were more likely to show radiologic interstitial lung abnormalities than those without (16% versus 5%; P = .001). Evaluation of background lung parenchyma may yield valuable and unanticipated information in patients undergoing surgical resections for lung masses that may correlate with radiographic interstitial lung abnormalities and influence clinical management.