Peh, WCG

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Title Radiological conference. Right upper lobe collapse due tobronchogenic carcinomaAuthor(s) Peh, WCGCitation Hong Kong Practitioner, 1996, v. 18 n. 8, p. 423-426Issued Date 1996URL http://hdl.handle.net/10722/44651Rights Creative Commons: Attribution 3.0 Hong Kong LicenseRADIOLOGICAL CONFERENCEClinical History:A 71 -year-old woman presented with dyspnoea and cough. She also had recent weight loss and anorexia.Figure 1: Frontal chest radiosraphWhat is the diagnosis?a) Right upper lobe collapse due to bronchogenic carcinomab) Lung infarctionc) Progressive massive fibrosisd) Radiation pneumonitise) Lobar pneumonia.This radiology case was prepared by: Dr. Wilfred C.G. Peh, Associate Professor,Department of Diagnostic Radiology,The University of Hong Kong,Queen Mary Hospital.(Continued on page 425)423Hong Kong Practitioner 18 (8) August 1996Answer:a) Right upper lobe collapse due to bronchogeniccarcinoma.Radiological findingsThe frontal chest radiograph (Fisures 1 and 2) shows ahomogeneous opacity in the upper zone of the right lungfield. It has a sharply-defined lower border formed byelevation of the horizontal fissure. Other evidence ofvolume loss includes deviation of the trachea to the rightand compensatory hyperinflation of the right middle andlower lobes. The cause of the right upper lobe collapsewas a proximally-located bronchogenic carcinoma, whichproduces the reverse S-shaped curve (S sign of Golden)seen on the frontal radiograph.Figure 2: This figure is identical to Figure 1 withaddition of arrows. The displacedhorizontal fissure (small white arrows)forms the upwardly-convex lower borderof the collapsed right upper lobe. Bulgingof the medial end of the displacedhorizontal fissure, from mass effect of thecausative bronchogenic carcinoma (curvedarrow) produces the S sign of Golden.Deviation of the trachea towards the right(arrowheads) is presentDiscussionCollapse (or atelectasis) refers to partial or completeloss of volume in a lung with diminished volume of air. Incontrast, consolidation implies a reduced amount of airassociated with normal lung volume. Pare and Fraserdescribed 4 mechanisms of lung collapse, namely:(1) Passive collapse secondary to air or fluid collectionin the pleural space;(2) Cicatrization collapse due to decreased lungcompliance e.g. in pulmonary fibrosis,-(3) Adhesive collapse from decreased alveolar surfacetension e.g. respiratory distress syndrome; and(4) Resorption collapse resulting from bronchial obstructionwhere gases in the distal alveoli are continuouslyresorbed without being replenished. Bronchogenictumours are an important cause of the last-mentionedtype of collapse.On chest radiographs, the only direct sign of collapse isdisplacement of the interlobar fissure. In right upper lobecollapse seen in our patient, the horizontal fissure, which isusually horizontally-orientated at the level of the anteriorend of the right fourth rib, is elevated and bowedupwards. The upper half of the oblique fissure isdisplaced forwards, pivoting about the hilum,- this lattersign may be appreciated on the lateral radiograph.Indirect signs of lobar collapse include:(1) loss of aeration, seen as increased density of thecollapsed lung;(2) crowding of blood vessels in partial lobar collapse;(3) crowding of bronchi, best appreciated where an airbronchogram is present;(4) mediastinal displacement, evidenced by trachealdeviation in upper lobe collapse;(5) compensatory hyperinflation of the adjacent normal| lung,- and(6) elevation of the hemidiaphragm, usually seen in lowerlobe collapse.Lung collapse can be caused by various types oftumours, inflammatory conditions, mucous plugging from425Radiological ConferenceRADIOLOGICAL CONFERENCEdifferent aetiolgies, foreign body inhalation and miscellaneousdiseases. In an older patient presentins with persistent lobarcollapse or recurrent pneumonia, the possible diagnosis ofbronchogenic carcinoma should always be considered first.The appropriate line of further investigation can then bepursued.Lung infarctionLung infarction occurs in 10-15% of patients withpulmonary thromboembolism. It is more likely to developin the presence of cardiopulmonary disease withobstruction of pulmonary venous outflow. The lowerlobes are predominantly affected. Chest radiographicsigns are generally non-specific and include segmentallydistributed consolidation, associated cavitation ofinfarcted lung, pleural effusion and elevation of theipsilateral hemidiaphragm. A sign said to be highlycharacteristic but uncommonly seen is the " HamptonHump". This refers to a pleural-based cone-shapedconsolidation located in the costophrenic sulus. In thiscase, the clinical presentation, lack of predisposingfeatures, and site of lesion are against the diagnosis oflung infarction.Progessive massive fibrosis (PMF)PMF develops or progresses as a complication ofpneumoconiosis. The lesion is located almost exclusively ineither the posterior segment of the upper lobe or thesuperior segment of the lower lobe. PMF is usually seenas bilaterally distributed large confluent shadows, whichmigrate towards the hila with time. The remainder of thelungs have background nodular opacities due topneumoconiosis. None of these features were present inthis case.Radiation pneumonitisAcute changes of radiation pneumonitis are usuallyseen a month or so post-treatment, taking up to 6 monthsto appear. Consolidation, corresponding to shape of theradiation portal, develops initially. This is followed byfibrosis, which is complete by 9-12 months. If severe,fibrosis may produce significant volume loss andmediastinal shift. The diagnosis of radiation pneumonitisis based on the history and its characteristic radiographicshape, features not present in this case.Lobar pneumoniaLobar pneumonia is demonstrated radiographically asconsolidation involving the air spaces of an anatomicallyrecognizable lobe. The commonest causative organism isStreptococcus pneumoniae, which produces unilobarpneumonia. Klebsiella pneumoniae tends to involvemultiple lobes, often cavitate and causes lobarenlargement. Staphyiococcal aureus affects children, withpneumatocoeles, empyema and pneumothorax beingcommon Complications. If the entire lobe is not involvedor if there is associated segmental collapse, lobarpneumonia may superficially resemble lobar collapse. Inthis case, the lack of clinical features of infection andtypical radiographic signs of an upper lobe collapse dueto obstructing tumour excludes this condition. •ReferencesPare JAP, Fraser RG. Roent3enologic signs of atelectasis. In: Synopsis ofDiseases of the Chest. Philadelphia: WB Saunders Co. 1983; pp 178-188.Eisenberg RL. S sign of Golden. In: Atlas of Signs in Radiology.Philadelphia: JB Lippincott Co. 1984; pp 264.Rubens MB. The pleura-collapse and consolidation. In: Sutton D (ed). ATextbook of Radiology and Imaging. 4th ed. Edinburgh: ChurchillLivingstone. 1987; pp 392-420.Dahnert W. Radiology Review Manual. 2nd ed. Baltimore: Williams &Wilkins. 1993; pp 262-263.4?fi

Radiological conference. Right upper lobe collapse due to bronchogenic carcinoma

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Radiological conference. Right upper lobe collapse due to bronchogenic carcinoma

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