title: Right hilar pseudomass due to partial right lower lobe atelectasis.
abstract: In cases of right lower lobe atelectasis, in which the lobe remains partially aerated, rotation of the right hilum into an anteroposterior plane can result in the formation of a "pseudomass" in the right hilar region on the frontal radiograph. Failure to recognize this variant appearance of right lower lobe atelectasis can result in a false diagnosis of a hilar mass and result in an unnecessary workup for lung cancer. Familiarity with this variant appearance of right lower lobe atelectasis, coupled with careful comparison with recent normal chest radiographs, should allow a correct diagnosis of a "pseudomass" in most cases. Computed tomography of the thorax can reliably exclude a hilar mass in cases in which recent normal chest radiographs are unavailable for comparison.
authors: Radiology Service, Lexington VA Medical Center, KY 40511, USA. johnwoodring@aol.com
authors: J H
authors: JH
authors: Woodring
mesh_terms: D000328:Adult; D000368:Aged; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008168:Lung / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000175:diagnosis; D008297:Male; D001261:Pulmonary Atelectasis / Q000000981:diagnostic imaging* / Q000473:pathology; D011859:Radiography