Centrilobular Emphysema With Walls: Are We Breaking Old School Norms?

Abstract

INTRODUCTION: Thin-walled cystic lung disease is defined as low attenuation lesions in the lung parenchyma with discernable walls having a thickness of <2-3mm. Centrilobular emphysema appears different since it lacks both cyst walls and presence of central core vessels. We present two cases with radiographic findings typical of lymphangioleiomyomatosis (LAM) but biopsy revealing centrilobular emphysema (CLE). CASE PRESENTATION: Case 1: A 34-year-old with 12 pack-year cigarette smoking history and occasional marijuana smoking was incidentally discovered to have thin walled lung cysts in the lung bases and no renal lesions on an abdominal computed tomography (CT). She had no respiratory symptoms. A high resolution chest CT (HRCT) showed multiple uniform thin walled cysts scattered diffusely in both lungs. There were no features of connective tissue disease or skin lesions. She had a surgical lung biopsy to confirm LAM but the pathology showed centrilobular emphysema with respiratory bronchiolitis. Case 2: A 40-year-old Caucasian female with a 15 pack-year smoking history also was found to have incidentally detected lung cysts on an abdominal CT abdomen performed for infectious colitis. She had mild exertional dyspnea only. Chest HRCT showed numerous thin-walled uniform cysts in both lungs. She had normal lung function and diffusion capacity. The leading diagnostic consideration was sporadic LAM. However surgical lung biopsy revealed centrilobular emphysema. DISCUSSION: With HRCT, a diagnostic etiology of cystic lung disease can be predicted in 80% of cases and approaches 100% in those with emphysema1. The most prominent differential diagnosis of thin-walled cystic lung disease includes CLE, LAM, pulmonary langerhan's histiocytosis X, lymphoid interstitial pneumonia, and Birt-Hogg-Dube. Centrilobular emphysema has characteristic features of lack of cyst wall, upper lobe predominance and presence of centrilobular vessel. Here we present two histopathologically proven cases of centrilobular emphysema with walls, radiologically mimicking LAM in young smoking women. Clinically these patients were relatively asymptomatic, with normal lung function. CONCLUSIONS: Centrilobular emphysema should be considered in the presence of uniform thin walled lung cysts in patients with a smoking history. Open lung biopsy may be warranted to rule out other etiologic diagnosis like LAM or PLCH if they do not have classic radiologic features.of centrilobular emphysema.