Computed tomography characteristics of primary pulmonary lymphoepithelioma-like carcinoma in 41 patients

To assess the computed tomography (CT) findings of primary pulmonary lymphoepithelioma-like carcinoma (LELC).

Clinical information and CT findings of 41 patients with pulmonary LELC were reviewed. CT images of 2 or 5mm thickness were obtained with a pre-treatment CT and were jointly evaluated by two radiologists.

Thirty central tumors and 11 peripheral tumors with diameters ranging from 1.0 to 8.7cm (mean, 4.1±1.9cm) were identified. Central tumors appeared to be larger than peripheral tumors (P=0.017). Tumors occurred more frequently in right middle lobe (31.7%) and left lower lobe (29.3%). CT findings of patients with early stage were similar to those observed in patients with advanced stage except that lymphadenopathy was significantly more common in patients with advanced stage. CT findings of pulmonary LELC consisted of well defined border (63.4%), lobulation (78.0%), vascular or bronchial encasement (43.9%), obstructive pneumonia (41.5%), pleural effusion (12.2%) and calcification (4.9%). On contrast-enhanced CT scans, inhomogeneously enhanced tumors were significantly larger than homogeneously enhanced tumors (P<0.001). Lymphadenopathy was seen in 28 patients, and lymph nodes with homogeneous enhancement were observed in 24/28 patients. Enlarged lymph nodes were more frequently occurred in peribronchial or hilar nodes (53.7%), subcrinal nodes (39.0%), right lower paratracheal nodes (31.7%) and right upper paratracheal nodes (22.0%).

Pulmonary LELC usually appeared as a large, central, well defined and lobulated tumor with vascular or bronchial encasement and obstructive pneumonia. Calcification was rare in pulmonary LELC. Lymphadenopathy was common, usually with homogeneous enhancement.