title: Analysis of the internal structure of peripheral pulmonary lesions using endobronchial ultrasonography.
abstract: OBJECTIVE
  To correlate the internal structure of peripheral pulmonary lesions, as visualized by endobronchial ultrasonography (EBUS), and the histology of the surgical specimen to develop a classification system for distinguishing benign from malignant lesions by EBUS.
  
  
  METHODS
  Retrospective review.
  
  
  METHODS
  A national hospital.
  
  
  METHODS
  One hundred twenty-four patients with peripheral pulmonary lesions who had undergone EBUS in whom a definitive histologic diagnosis was made. In 69 patients, EBUS findings were correlated with the histology of a surgical specimen.
  
  
  METHODS
  EBUS was performed by a miniature probe (20-MHz) introduced up to the lesion through a channel in a bronchoscope.
  
  
  RESULTS
  Three classes and six subclasses of lesions were identified by EBUS based on the internal structure of the lesion, focusing on internal echoes, vascular and bronchial patency, and the morphology of the hyperechoic areas, reflecting air in the alveoli and bronchioles. The classes of lesions are as follows: type I, homogeneous pattern (type Ia, with patent vessels and patent bronchioles; type Ib, without vessels and bronchioles); type II, hyperechoic dots and linear arcs pattern (type IIa, without vessels; type IIb, with patent vessels); and type III, heterogeneous pattern (type IIIa, with hyperechoic dots and short lines; type IIIb, without hyperechoic dots and short lines). Twenty-three of 25 type I lesions (92.0%) were benign, while 98 of 99 type II and III lesions (99.0%) were malignant. Twenty-one of 24 type II lesions (87.5%) were well-differentiated adenocarcinomas, and all type IIIb lesions were malignant, including 18 poorly differentiated adenocarcinomas (81.8%).
  
  
  CONCLUSIONS
  EBUS permits the visualization of the internal structure of peripheral pulmonary lesions, and this information suggests the histology of the lesion.
authors.affiliation: Department of Surgery, National Hiroshima Hospital, 513 Jike, Saijyoucyou, Higashi-Hiroshima City, Hiroshima Prefecture, 739-0041 Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kurimoto
authors.forename: Masaki
authors.initials: M
authors.lastname: Murayama
authors.forename: Shinkichiro
authors.initials: S
authors.lastname: Yoshioka
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishisaka
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology; D001999:Bronchoscopy; D019160:Endosonography / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D012189:Retrospective Studies