title: Diagnosis of peripheral lung cancer with three echoic features via endobronchial ultrasound.
abstract: BACKGROUND
  Endobronchial ultrasonography (EBUS) is useful in localizing peripheral lung lesions. Previous reports have revealed that several characteristic echoic patterns correlate well with the histopathologic findings of benign and malignant lesions. Therefore, EBUS may be also useful in the differential diagnosis of malignant lesions of the lung.
  
  
  OBJECTIVE
  To assess the feasibility of EBUS in the differential diagnosis between malignant and benign lesions by the following three characteristic echoic features indicating malignancy: continuous margin; absence of a linear-discrete air bronchogram; and heterogeneous echogenicity.
  
  
  METHODS
  EBUS images from 224 patients who undergone bronchoscopy for a peripheral lung lesion were analyzed. The sensitivity and specificity for each echoic feature or in combination in diagnosing malignancy or benignity were determined.
  
  
  RESULTS
  Continuous margin, absence of linear-discrete air bronchogram, and heterogeneous echogenicity are three echoic features indicating malignancy. The absence of linear-discrete air bronchogram has the highest sensitivity in the diagnosis of malignancy (91.9%), but the lowest specificity (62.4%). By contrast, a well-defined margin has the highest specificity (93.1%), but the lowest sensitivity (27.6%). The sensitivity and specificity for heterogeneous echogenicity are intermediate (65.0% and 90.1%, respectively). The negative predictive value for the malignancy of a lesion with none of these three echoic features is 93.7%. The positive predictive value for malignancy of a lesion with any two of the three echoic features is 89.2%.
  
  
  CONCLUSIONS
  These results indicate that EBUS is useful as an adjunct in lung cancer diagnosis, especially when peripheral lung lesions are not visible in traditional bronchoscopy.
authors.affiliation: Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung School of Medicine, 199 Tun-Hwa N Rd, Taipei, Taiwan.
authors.forename: Chih-Hsi
authors.initials: CH
authors.lastname: Kuo
authors.forename: Shu-Min
authors.initials: SM
authors.lastname: Lin
authors.forename: Ho-Chien
authors.initials: HC
authors.lastname: Chen
authors.forename: Chu-Liang
authors.initials: CL
authors.lastname: Chou
authors.forename: Chih-Ten
authors.initials: CT
authors.lastname: Yu
authors.forename: Han-Pin
authors.initials: HP
authors.lastname: Kuo
mesh_terms: D001999:Bronchoscopy; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D015331:Cohort Studies; D003937:Diagnosis, Differential; D019160:Endosonography; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results