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Computed tomographic diagnosis of rounded atelectasis: A case report
Compurerized Radio/. Vol. 7, No. 5, pp. 301-304, Printed in the U.S.A. All rights reserved
COMPUTED
1983
Copyright
0730-4862/83 $3.00 + 0.00 1983 Pergamon Press Ltd
TOMOGRAPHIC DIAGNOSIS OF ROUNDED ATELECTASIS: A CASE REPORT WILLIAM
Department
0
of Radiology, (Rrcrirrd
Brooke
S. GRABOWSKI
Army Medical
16 June 1982; receiued,fiw
Center,
Fort Sam, Houston,
publication
16 Frhruary
TX 78234. U.S.A
1982)
Abstract -A case of rounded atelectasis of the lung is presented in which the diagnosis was made following computed tomography. This imaging technique enabled differentiation of this benign condition from other causes of lung masses. In certain cases where diagnosis is difficult by conventional means, CT may prove helpful and prevent unnecessary surgery. Round
atelectasis
CT, lung
Lungs, collapse
INTRODUCTION
Rounded atelectasis (RA) is a recently described entity in American literature with fairly specific signs to indicate its presence. Diagnosis of this entity, which usually presents as a mass, is important because of its benignity, saving the patient an unnecessary surgical procedure. Previous reports have emphasized the use of conventional tomography, with computed tomography (CT) only playing a confirmatory role. Recently, a case was presented which had confusing conventional tomographic findings and a specific diagnosis was accomplished by utilization of CT. CASE
REPORT
A 64-yr old white male was evaluated for a mass found in his right lung at another hospital after having given a history of swallowing a tooth. He was retired from the Navy after 20 years as a cook and for the last 23 years had worked as a printer for a newspaper. He had a 40-pack/year history of smoking, but had quit 2 years previously. Evaluation included negative sputum cytologies, bronchoscopy, mediastinoscopy, and brain, liver and bone scans. He was transferred to Brooke Army Medical Center for evaluation. Routine chest roentgenograms (Fig. 1) showed bilateral pleural thickening with calcification and with a 2.5 cm rounded mass in the right lung, which on AP (Fig. 2) and lateral linear tomography, appeared to occupy the wall of a large cavity. The provisional diagnosis was carcinoma of the lung in a patient with probable asbestosis. There was no history of hemothorax or trauma, and skin testing and sputum samples were negative for tuberculosis. A CT (GE 8800) scan (Fig. 3) was performed in an effort to gain further information. The mass was seen to occupy an intrathoracic position adjacent and partially connected to the point of maximum pleural thickening on the lateral portion of the middle lobe. The total volume of the right lung was reduced. No large bullous cavity near the mass was present. The most striking abnormality, however, was the distribution of pulmonary vessels which curved around the mass as if being drawn toward and into it, leaving the surrounding lung hypovascular and hyperexpanded. The diagnosis of rounded atelectasis in a patient with asbestosis was made. Re-evaluation of the conventional tomograms showed a “comet” sign to be present inferiorly. Because of unfamiliarity with this entity, a percutaneous needle biopsy was requested. This produced some atypical cells suggesting adenocarcinoma to the cytologist, and because of this a thoracotomy was performed. At operation, there were dense fibrous adhesions of the pleura, and in the area of the lesion, only contracted lung with atelectasis secondary to scar tissue was present in The opinions or assertions contained herein are the private views of the author view of the Department of the Army or the Department of Defense. 301
and are not to be construed
as reflecting
the
302
WILLIAM S. GRABOWSKI
Fig. 1. PA chest shows bilateral
pleural
thickening and a 2.5 cm rounded middle lobe.
mass in the region
of the right
the middle lobe. No tumor was seen. Pathologic analysis of the pleura and lung showed chr ‘0 nit inflammatory aggregates, fibroconnective tissue, interstitial fibrosis and hemorrhage, intra-alveolar hemorrhage and foci of organizing pneumonia. Iron stains for ferruginous bodies were negative. Evaluation with an electron microscope found only one asbestos fiber. A small focus of carcinoid tumor was found adjacent to a bronchus. DISCUSSION Rounded atelectasis is an uncommon entity with rather specific radiographic findings, which have been described in detail in recent papers [l-3]. The most characteristic feature of this entity, on conventional tomograms, is “the comet-tail” sign formed by the arcuate course of pulmonary vessels and bronchi as they enter rne mass, usually on the inferior pole. CT, however, has the capability of demonstrating this comet-like characteristic around the total circumference of the mass. The essence of RA is loss of volume centered about the mass. As shown easily by CT, the effect of RA upon surrounding parenchyma, vessels and bronchi is to cause curving of vessels toward and around the mass to converge at the pleural margin. This involves vessels not only of the lobe involved, but may affect other nearby lobes (1). The appearance suggests talons grasping the mass. These signs of volume loss are not so easily detected by conventional means unless arteriography or bronchography is employed. Hyperlucency of surrounding parenchyma and overall loss of lung volume may be more apparent by CT [9, lo]. Other etiologies of masses will either cause the vessels to take the shortest route to the hilum or cause the displacement and divergence of vessels [3]. With this patient’s suggestive history and the presence of calcified bilateral pleural plaques, asbestosis was strongly suggested [I44lo]. An association of rounded atelectasis and asbestosis has recently been described [2]. Inability to demonstrate asbestos fibers in this case could be due to multiple causes, such as sampling error, location, disintegration of fibers, and difficulty in identification for technical reasons [l 1, 123.
Fig. 2. AP linear tomogram margin of the cavity (arrow)
suggests a mass bordering a large bulla. Apparent thickening of the inferior in retrospect is actually vessels and bronchi entering the inferior margin of rounded atelectasis (“comet sign”).
Fig. 3. At setting for maximum visualization of lung parenchyma, the pulmonary vasculature surrounds the mass and appears to be pulled into it, giving an appearance similar to talons. leaving the rest of the lung hypovascular. The mass is connected to the point of maximum pleural thickening and no large cavity was seen. 303
304
WILLIAM S. GRABOWSKI
RA, a rare entity, can be diagnosed by conventional radiographic techniques. However, in cases where the diagnosis of RA may be difficult or only suspected, CT may produce a dramatic picture which allows a rapid and virtually certain diagnosis. REFERENCES 1. A. J. Schneider, B. Felson and L. L. Gonzales, Rounded atelectasis, Am. J. Roentg. 134, 225-232 (1980). 2. R. A. Mintzer, R. M. Gore, R. L. Vogelzang and S. Holz, Rounded atelectasis and its association with asbestosis-induced pleural disease, Radiology 139, 5677570 (1981). 3. Hanke and R. Kretzschmar, Round atelectasis, Semin. Roentg. 15, 174182 (1980). 4. K. Ellis and M. Walff, Mesotheliomas and secondary tumors of the pleura, Semin. Roentg. 12, 3033311 (1977). 5. E. N. Sargent, G. Jacobson and J. S. Gordonson, Pleural plaques: a signpost of asbestos dust inhalation, Semin. Roentg. 12, 287-297 (1977). 6. I. M. Freudlich and R. R. Greening, Asbestosis and associated medical problems, Radiology 89, 224229 (1977). 7. M. Hurwitz, Roentgenologic aspects of asbestosis, Am. J. Roentg. 85, 256262 (1961). 8. L. Kreel, Computer tomography in evaluation of pulmonary asbestosis: preliminary experiences with the EMI general purpose scanner, Acta radial. (Diagn.) 17, 405-412 (1976). 9. L. Kreel, Computed tomography of the lung and pleura, Semin. Roentg. 13, 213-225 (1978). 10. L. Kreel, Computed tomography of the thorax, Radial. Clin. N. Am. 16, 575-584 (1978). 11. A. P. Fishman, Pulmonary Diseases and Disorders, pp. 77@779, McGraw-Hill, New York (1980). 12. H. Spencer, Pathology of the Lung, pp. 434440. Pergamon Press, Oxford (1968). S. GRABOWSKI received a B.S. from the United States Military Academy in 1968 and an M.D. from Emory University in 1975. Dr Grabowski completed his residency in radiology at Walter Reed Army Medical Center in 1979. Between 1979 and 1981, he served as Chief of Chest Radiology at Brooke Army Medical Center. At present, Dr Grabowski is the Chief of Radiology at Brooke Army Medical Center and Consultant in Radiology to the Army’s Health Services Command.
About the Author-WrLLlm
COMPUTED
1983
Copyright
0730-4862/83 $3.00 + 0.00 1983 Pergamon Press Ltd
TOMOGRAPHIC DIAGNOSIS OF ROUNDED ATELECTASIS: A CASE REPORT WILLIAM
Department
0
of Radiology, (Rrcrirrd
Brooke
S. GRABOWSKI
Army Medical
16 June 1982; receiued,fiw
Center,
Fort Sam, Houston,
publication
16 Frhruary
TX 78234. U.S.A
1982)
Abstract -A case of rounded atelectasis of the lung is presented in which the diagnosis was made following computed tomography. This imaging technique enabled differentiation of this benign condition from other causes of lung masses. In certain cases where diagnosis is difficult by conventional means, CT may prove helpful and prevent unnecessary surgery. Round
atelectasis
CT, lung
Lungs, collapse
INTRODUCTION
Rounded atelectasis (RA) is a recently described entity in American literature with fairly specific signs to indicate its presence. Diagnosis of this entity, which usually presents as a mass, is important because of its benignity, saving the patient an unnecessary surgical procedure. Previous reports have emphasized the use of conventional tomography, with computed tomography (CT) only playing a confirmatory role. Recently, a case was presented which had confusing conventional tomographic findings and a specific diagnosis was accomplished by utilization of CT. CASE
REPORT
A 64-yr old white male was evaluated for a mass found in his right lung at another hospital after having given a history of swallowing a tooth. He was retired from the Navy after 20 years as a cook and for the last 23 years had worked as a printer for a newspaper. He had a 40-pack/year history of smoking, but had quit 2 years previously. Evaluation included negative sputum cytologies, bronchoscopy, mediastinoscopy, and brain, liver and bone scans. He was transferred to Brooke Army Medical Center for evaluation. Routine chest roentgenograms (Fig. 1) showed bilateral pleural thickening with calcification and with a 2.5 cm rounded mass in the right lung, which on AP (Fig. 2) and lateral linear tomography, appeared to occupy the wall of a large cavity. The provisional diagnosis was carcinoma of the lung in a patient with probable asbestosis. There was no history of hemothorax or trauma, and skin testing and sputum samples were negative for tuberculosis. A CT (GE 8800) scan (Fig. 3) was performed in an effort to gain further information. The mass was seen to occupy an intrathoracic position adjacent and partially connected to the point of maximum pleural thickening on the lateral portion of the middle lobe. The total volume of the right lung was reduced. No large bullous cavity near the mass was present. The most striking abnormality, however, was the distribution of pulmonary vessels which curved around the mass as if being drawn toward and into it, leaving the surrounding lung hypovascular and hyperexpanded. The diagnosis of rounded atelectasis in a patient with asbestosis was made. Re-evaluation of the conventional tomograms showed a “comet” sign to be present inferiorly. Because of unfamiliarity with this entity, a percutaneous needle biopsy was requested. This produced some atypical cells suggesting adenocarcinoma to the cytologist, and because of this a thoracotomy was performed. At operation, there were dense fibrous adhesions of the pleura, and in the area of the lesion, only contracted lung with atelectasis secondary to scar tissue was present in The opinions or assertions contained herein are the private views of the author view of the Department of the Army or the Department of Defense. 301
and are not to be construed
as reflecting
the
302
WILLIAM S. GRABOWSKI
Fig. 1. PA chest shows bilateral
pleural
thickening and a 2.5 cm rounded middle lobe.
mass in the region
of the right
the middle lobe. No tumor was seen. Pathologic analysis of the pleura and lung showed chr ‘0 nit inflammatory aggregates, fibroconnective tissue, interstitial fibrosis and hemorrhage, intra-alveolar hemorrhage and foci of organizing pneumonia. Iron stains for ferruginous bodies were negative. Evaluation with an electron microscope found only one asbestos fiber. A small focus of carcinoid tumor was found adjacent to a bronchus. DISCUSSION Rounded atelectasis is an uncommon entity with rather specific radiographic findings, which have been described in detail in recent papers [l-3]. The most characteristic feature of this entity, on conventional tomograms, is “the comet-tail” sign formed by the arcuate course of pulmonary vessels and bronchi as they enter rne mass, usually on the inferior pole. CT, however, has the capability of demonstrating this comet-like characteristic around the total circumference of the mass. The essence of RA is loss of volume centered about the mass. As shown easily by CT, the effect of RA upon surrounding parenchyma, vessels and bronchi is to cause curving of vessels toward and around the mass to converge at the pleural margin. This involves vessels not only of the lobe involved, but may affect other nearby lobes (1). The appearance suggests talons grasping the mass. These signs of volume loss are not so easily detected by conventional means unless arteriography or bronchography is employed. Hyperlucency of surrounding parenchyma and overall loss of lung volume may be more apparent by CT [9, lo]. Other etiologies of masses will either cause the vessels to take the shortest route to the hilum or cause the displacement and divergence of vessels [3]. With this patient’s suggestive history and the presence of calcified bilateral pleural plaques, asbestosis was strongly suggested [I44lo]. An association of rounded atelectasis and asbestosis has recently been described [2]. Inability to demonstrate asbestos fibers in this case could be due to multiple causes, such as sampling error, location, disintegration of fibers, and difficulty in identification for technical reasons [l 1, 123.
Fig. 2. AP linear tomogram margin of the cavity (arrow)
suggests a mass bordering a large bulla. Apparent thickening of the inferior in retrospect is actually vessels and bronchi entering the inferior margin of rounded atelectasis (“comet sign”).
Fig. 3. At setting for maximum visualization of lung parenchyma, the pulmonary vasculature surrounds the mass and appears to be pulled into it, giving an appearance similar to talons. leaving the rest of the lung hypovascular. The mass is connected to the point of maximum pleural thickening and no large cavity was seen. 303
304
WILLIAM S. GRABOWSKI
RA, a rare entity, can be diagnosed by conventional radiographic techniques. However, in cases where the diagnosis of RA may be difficult or only suspected, CT may produce a dramatic picture which allows a rapid and virtually certain diagnosis. REFERENCES 1. A. J. Schneider, B. Felson and L. L. Gonzales, Rounded atelectasis, Am. J. Roentg. 134, 225-232 (1980). 2. R. A. Mintzer, R. M. Gore, R. L. Vogelzang and S. Holz, Rounded atelectasis and its association with asbestosis-induced pleural disease, Radiology 139, 5677570 (1981). 3. Hanke and R. Kretzschmar, Round atelectasis, Semin. Roentg. 15, 174182 (1980). 4. K. Ellis and M. Walff, Mesotheliomas and secondary tumors of the pleura, Semin. Roentg. 12, 3033311 (1977). 5. E. N. Sargent, G. Jacobson and J. S. Gordonson, Pleural plaques: a signpost of asbestos dust inhalation, Semin. Roentg. 12, 287-297 (1977). 6. I. M. Freudlich and R. R. Greening, Asbestosis and associated medical problems, Radiology 89, 224229 (1977). 7. M. Hurwitz, Roentgenologic aspects of asbestosis, Am. J. Roentg. 85, 256262 (1961). 8. L. Kreel, Computer tomography in evaluation of pulmonary asbestosis: preliminary experiences with the EMI general purpose scanner, Acta radial. (Diagn.) 17, 405-412 (1976). 9. L. Kreel, Computed tomography of the lung and pleura, Semin. Roentg. 13, 213-225 (1978). 10. L. Kreel, Computed tomography of the thorax, Radial. Clin. N. Am. 16, 575-584 (1978). 11. A. P. Fishman, Pulmonary Diseases and Disorders, pp. 77@779, McGraw-Hill, New York (1980). 12. H. Spencer, Pathology of the Lung, pp. 434440. Pergamon Press, Oxford (1968). S. GRABOWSKI received a B.S. from the United States Military Academy in 1968 and an M.D. from Emory University in 1975. Dr Grabowski completed his residency in radiology at Walter Reed Army Medical Center in 1979. Between 1979 and 1981, he served as Chief of Chest Radiology at Brooke Army Medical Center. At present, Dr Grabowski is the Chief of Radiology at Brooke Army Medical Center and Consultant in Radiology to the Army’s Health Services Command.
About the Author-WrLLlm