Rounded Atelectasis: Diagnosis by Fine-Needle Aspiration Cytology Wallace T. Miller, Jr., M.D.,Prabodh K. Gupta, M.D., Michael A. Grippi, M.D.,and Wallace T. Miller, M.D.
Rounded atelectasis, a rare, benign mass lesion, is most ofen seen in association with asbestos-related pleural changes. Often a presumptive diagnosis can be made on the basis of characteristic CT and chest radiographicfindings. However, not infrequently radiographic imaging fails to differntiate rounded atelectasisfrom primary bronchogenic carcinoma, a disease which is seen with increased frequency in patients with asbestos exposure. We describe two cases where the diagnosis of rounded atelectasis was made by fine-needle aspiration (FNA) cytology. The cytologic features included abundant pulmonary parenchymal material with thickened alveolar walls containing pulmonary macrophages and connective tissue. It is important to realize that this is a useful positive finding indicating rounded atelectasis, rather than a negative finding suggesting the absence of neoplasm. Needles with a cutting action may be necessary to obtain suficient material to make the diagnosis of rounded atelectasis. Diagn Cytopathol 1992;8:617620. @ 1992 Wiley-Liss, Inc. Key Words: Bilateral pleural disease; Asbestos exposure; Chest CT; Wescott needle
In two patients, fine-needle aspiration (FNA) was requested because of lower lobe masses. Differential diagnosis included rounded atelectasis and primary bronchogenic carcinoma. Case 1 was a 75-yr-old man without known asbestos exposure but with a 50 pack/yr history of smoking. He presented with left-sided pleuritic chest pain and a left lower lobe mass which was documented to be radiographically stable for 8 mo. Bronchoscopy had been Received October 10, 1991. Accepted February 28, 1992. From the Department of Radiology, the Cytopathology and Cytometry Section, Department of Pathology and Laboratory Medicine, and the Pulmonary and Critical Care Section, Department of Medicine, University of Pennsylvania Medical Center, Philadelphia, PA. Address reprint requests to Prabodh K. Gupta, M.D., Cytopathology and Cytometry Section, Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, F.6.037 Founders Pavilion, 3400 Spruce St., Philadelphia, P A 19104-4283.
6) 1992 WILEY-LISS, I N C
performed twice revealing no bronchoscopically detectable abnormality. Chest CT revealed bilateral pleural disease with a nonspecific pulmonary mass (Fig. la). He subsequently underwent FNA evaluation. Case 2 was a 65-yr-old man with a 30 pack/yr history of smoking and exposure to asbestos as a construction worker. An asymptomatic left lower lobe mass was detected by an abdominal plain film during an evaluation for nonspecific abdominal pain. Chest CT showed a left lower lobe mass with features suggestive, but not diagnostic, of rounded atelectasis and bilateral pleural plaques (Fig. lb). FNA was performed using a 19-cm, 22-gauge Wescott needle.
Cytology The cytologic features in both cases were similar. The aspirates included abundant pulmonary material occurring in large tissue fragments and clumps (Fig. 2a). Distinct alveolar spaces were demonstrable. The alveolar spaces revealed some variation in size. The alveolar walls were thickened with dense connective tissue and few pulmonary macrophages (Fig. 2b). In the paraffin-processed cell blocks, some of the septa appeared hyalinized and acellular (Fig. 3). There was focal accumulation of lymphoid mononuclear cells in one case.
Discussion Rounded atelectasis is a mass-like lesion seen most commonly in the lower lobes and usually associated with asbestos-related pleural fibrosis, although rarely it can be seen with pleural fibrosis from other etiologies. Characteristically, there is a rounded mass-like area of atelectatic lung adjacent to an area of pleural fibrosis. The consistent relationship between pleural fibrosis and rounded atelectasis has suggested to some that progressive retraction of visceral pleural scarring results in folding and ate'~9~3'
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Fig. 1. (a) PA chest radiograph reveals a 6-cm right lower lobe mass. Note also the extensive pleural thickening which is characteristically associated with rounded atelectasis. (b)CT exam through the right lung base shows the mass closely associated with pleural thickening.
lectasis of the adjacent lung. 2,4,8,9 Surgical resection discloses a plaque-like region of fibrosis along the visceral pleura with a rounded area of surrounding atelectasis. Interdigitated within the region of atelectasis are multiple infoldings of visceral pleura, as if the lung surface was pleated and drawn together. 9,10 Histologically the atelectatic lung may be normal or fibrotic, consistent with asbestosis. Traditionally FNA has been used to establish a definitive diagnosis of malignancy in cases where rounded atelectasis is in the radiographic differential diagnoses. A ‘‘negative” cytologic aspirate has been used as a rationale to clinically and radiographically follow suspicious lesions as presumptive rounded atelectasis. In our cases we were able to make a diagnosis of rounded atelectasis by noting the appearance of atelectatic lung parenchyma in the cytologic aspirate specimen. Previous reports have noted that FNA of rounded atelectasis yielded “sparse” or “inconclusive” material or merely showed “no evidence of malignancy.” The lack of histiocytic giant cell response, necrosis, and inflammation in FNA smears helps differentiate this entity from other similar lesions including granulomas, organizing pneumonias, and the rheumatoid nodule. It is possible that the cutting action of the Wescott needle we employ is important in the positive diagnosis of rounded atelectasis. This needle has a side hole with a
’
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cutting edge. Once placed in the mass the stylette is removed and vigorous suction is applied with a 25-cc syringe during inward and outward movement of the needle through the lesion. This suction draws a small core of tissue into the needle lumen which is then excised by the cutting edge. As a consequence, it is possible to obtain small pieces of tissue which preserve the native morphology of the lesion. Noncutting needles, such as the Chiba, are less likely to provide enough tissue to make the diagnosis of atelectasis. Essential also are the clinical and radiographic characteristics of rounded atelectasis. There is no histologic feature which distinguishes rounded atelectasis from other atelectatic lung. We would also like to emphasize that FNA of normal, nonatelectatic lung generally does not produce the same cytologic/histologic appearance. The FNA samples are extremely scant and it is unlikely that material obtained from nonatelectatic lung would be of sufficient volume to retain the morphologic features. In summary, in the appropriate clinical situation, the cytohistologic appearance of atelectasis on specimens obtained from FNA should be considered a positive diagnosis of rounded atelectasis. This is a more definitive result than the mere absence of neoplastic cells in the aspirate. Needles with a cutting action may be necessary to obtain sufficient material to make this diagnosis.
ROUNDED ATELECTASIS: DIAGNOSIS BY FNA CYTOLOGY
Fig. 2. (a) FNA specimen, case 1. Notice the abundant pulmonary material occurring in large tissue fragments (Millipore filter, Papanicolaou, X 110). (b) FNA specimen, case 1. Higher magnification of Figure 2a. Notice the multiple alveolar spaces with thickened cellular walls and scarring. The specimen is thick and only one profile is focused (Millipore filter, Papanicolaou, x 400).
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Fig. 3. F N A specimen, case 2. Paraffin-processed cell block revealing hyalinized and scarred pulmonary alveolar spaces (hematoxylin-eosin, X 400).
References 1. McHugh K, Blaquiere RM. CT features of rounded atelectasis. AJR
1989;153:257-260. 2. Mintzer RA, Gore RM, Vogelzang RL, Holz S . Rounded atelectasis and its association with asbestos-induced pleural disease. Radiology 1981;139:567-570. 3. Tylen U, Nilsson U. Computed tomography in pulmonary pseudotumors and their relation to asbestos exposure. J Comput Assist Tomogr 1982; 6(2):229-237. 4.. Lynch DA, Gamsu G, Ray CS, Aberle DR. Asbestos-related focal lung masses: Manifestations on conventional and high-resolution CT scans. Radiology 1988;169:603-607. 5. Selikoff IJ. Cancer risk of asbestos exposure. In: Hiatt HH, Watson
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JD, Winsten JA, eds. Origins of human cancer. New York: Cold Spring Harbor Laboratory, 1977:1765-1784. 6. Hillerdal G. Rounded atelectasis. Clinical experience with 74 patients. Chest 1989;95:836-841. 7. Stancato-Pasik A, Mendelson DS, Marom Z. Rounded atelectasis caused by histoplasmosis. AJR 1990;155(2):275-276. 8. Menzies R, Fraser R. Rounded atelectasis: Pathologic and pathogenetic features. Am J Surg Pathol 1987;11:674681.
9. Dernevik L, Gatzinsky P. Pathogenesis of shrinking pleuritis with atelectasis-"rounded atelectasis." Eur J Respir Dis 1987;71:244 249. 110. Case Records of the Massachusetts General Hospital (Case 241983). N Engl J Med 1983;308(24):1466-1472.
Rounded atelectasis, a rare, benign mass lesion, is most ofen seen in association with asbestos-related pleural changes. Often a presumptive diagnosis can be made on the basis of characteristic CT and chest radiographicfindings. However, not infrequently radiographic imaging fails to differntiate rounded atelectasisfrom primary bronchogenic carcinoma, a disease which is seen with increased frequency in patients with asbestos exposure. We describe two cases where the diagnosis of rounded atelectasis was made by fine-needle aspiration (FNA) cytology. The cytologic features included abundant pulmonary parenchymal material with thickened alveolar walls containing pulmonary macrophages and connective tissue. It is important to realize that this is a useful positive finding indicating rounded atelectasis, rather than a negative finding suggesting the absence of neoplasm. Needles with a cutting action may be necessary to obtain suficient material to make the diagnosis of rounded atelectasis. Diagn Cytopathol 1992;8:617620. @ 1992 Wiley-Liss, Inc. Key Words: Bilateral pleural disease; Asbestos exposure; Chest CT; Wescott needle
In two patients, fine-needle aspiration (FNA) was requested because of lower lobe masses. Differential diagnosis included rounded atelectasis and primary bronchogenic carcinoma. Case 1 was a 75-yr-old man without known asbestos exposure but with a 50 pack/yr history of smoking. He presented with left-sided pleuritic chest pain and a left lower lobe mass which was documented to be radiographically stable for 8 mo. Bronchoscopy had been Received October 10, 1991. Accepted February 28, 1992. From the Department of Radiology, the Cytopathology and Cytometry Section, Department of Pathology and Laboratory Medicine, and the Pulmonary and Critical Care Section, Department of Medicine, University of Pennsylvania Medical Center, Philadelphia, PA. Address reprint requests to Prabodh K. Gupta, M.D., Cytopathology and Cytometry Section, Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, F.6.037 Founders Pavilion, 3400 Spruce St., Philadelphia, P A 19104-4283.
6) 1992 WILEY-LISS, I N C
performed twice revealing no bronchoscopically detectable abnormality. Chest CT revealed bilateral pleural disease with a nonspecific pulmonary mass (Fig. la). He subsequently underwent FNA evaluation. Case 2 was a 65-yr-old man with a 30 pack/yr history of smoking and exposure to asbestos as a construction worker. An asymptomatic left lower lobe mass was detected by an abdominal plain film during an evaluation for nonspecific abdominal pain. Chest CT showed a left lower lobe mass with features suggestive, but not diagnostic, of rounded atelectasis and bilateral pleural plaques (Fig. lb). FNA was performed using a 19-cm, 22-gauge Wescott needle.
Cytology The cytologic features in both cases were similar. The aspirates included abundant pulmonary material occurring in large tissue fragments and clumps (Fig. 2a). Distinct alveolar spaces were demonstrable. The alveolar spaces revealed some variation in size. The alveolar walls were thickened with dense connective tissue and few pulmonary macrophages (Fig. 2b). In the paraffin-processed cell blocks, some of the septa appeared hyalinized and acellular (Fig. 3). There was focal accumulation of lymphoid mononuclear cells in one case.
Discussion Rounded atelectasis is a mass-like lesion seen most commonly in the lower lobes and usually associated with asbestos-related pleural fibrosis, although rarely it can be seen with pleural fibrosis from other etiologies. Characteristically, there is a rounded mass-like area of atelectatic lung adjacent to an area of pleural fibrosis. The consistent relationship between pleural fibrosis and rounded atelectasis has suggested to some that progressive retraction of visceral pleural scarring results in folding and ate'~9~3'
Diagnostic Cytopathology, Vol 8, No 6
611
MKLLER ET AL.
Fig. 1. (a) PA chest radiograph reveals a 6-cm right lower lobe mass. Note also the extensive pleural thickening which is characteristically associated with rounded atelectasis. (b)CT exam through the right lung base shows the mass closely associated with pleural thickening.
lectasis of the adjacent lung. 2,4,8,9 Surgical resection discloses a plaque-like region of fibrosis along the visceral pleura with a rounded area of surrounding atelectasis. Interdigitated within the region of atelectasis are multiple infoldings of visceral pleura, as if the lung surface was pleated and drawn together. 9,10 Histologically the atelectatic lung may be normal or fibrotic, consistent with asbestosis. Traditionally FNA has been used to establish a definitive diagnosis of malignancy in cases where rounded atelectasis is in the radiographic differential diagnoses. A ‘‘negative” cytologic aspirate has been used as a rationale to clinically and radiographically follow suspicious lesions as presumptive rounded atelectasis. In our cases we were able to make a diagnosis of rounded atelectasis by noting the appearance of atelectatic lung parenchyma in the cytologic aspirate specimen. Previous reports have noted that FNA of rounded atelectasis yielded “sparse” or “inconclusive” material or merely showed “no evidence of malignancy.” The lack of histiocytic giant cell response, necrosis, and inflammation in FNA smears helps differentiate this entity from other similar lesions including granulomas, organizing pneumonias, and the rheumatoid nodule. It is possible that the cutting action of the Wescott needle we employ is important in the positive diagnosis of rounded atelectasis. This needle has a side hole with a
’
618
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cutting edge. Once placed in the mass the stylette is removed and vigorous suction is applied with a 25-cc syringe during inward and outward movement of the needle through the lesion. This suction draws a small core of tissue into the needle lumen which is then excised by the cutting edge. As a consequence, it is possible to obtain small pieces of tissue which preserve the native morphology of the lesion. Noncutting needles, such as the Chiba, are less likely to provide enough tissue to make the diagnosis of atelectasis. Essential also are the clinical and radiographic characteristics of rounded atelectasis. There is no histologic feature which distinguishes rounded atelectasis from other atelectatic lung. We would also like to emphasize that FNA of normal, nonatelectatic lung generally does not produce the same cytologic/histologic appearance. The FNA samples are extremely scant and it is unlikely that material obtained from nonatelectatic lung would be of sufficient volume to retain the morphologic features. In summary, in the appropriate clinical situation, the cytohistologic appearance of atelectasis on specimens obtained from FNA should be considered a positive diagnosis of rounded atelectasis. This is a more definitive result than the mere absence of neoplastic cells in the aspirate. Needles with a cutting action may be necessary to obtain sufficient material to make this diagnosis.
ROUNDED ATELECTASIS: DIAGNOSIS BY FNA CYTOLOGY
Fig. 2. (a) FNA specimen, case 1. Notice the abundant pulmonary material occurring in large tissue fragments (Millipore filter, Papanicolaou, X 110). (b) FNA specimen, case 1. Higher magnification of Figure 2a. Notice the multiple alveolar spaces with thickened cellular walls and scarring. The specimen is thick and only one profile is focused (Millipore filter, Papanicolaou, x 400).
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Fig. 3. F N A specimen, case 2. Paraffin-processed cell block revealing hyalinized and scarred pulmonary alveolar spaces (hematoxylin-eosin, X 400).
References 1. McHugh K, Blaquiere RM. CT features of rounded atelectasis. AJR
1989;153:257-260. 2. Mintzer RA, Gore RM, Vogelzang RL, Holz S . Rounded atelectasis and its association with asbestos-induced pleural disease. Radiology 1981;139:567-570. 3. Tylen U, Nilsson U. Computed tomography in pulmonary pseudotumors and their relation to asbestos exposure. J Comput Assist Tomogr 1982; 6(2):229-237. 4.. Lynch DA, Gamsu G, Ray CS, Aberle DR. Asbestos-related focal lung masses: Manifestations on conventional and high-resolution CT scans. Radiology 1988;169:603-607. 5. Selikoff IJ. Cancer risk of asbestos exposure. In: Hiatt HH, Watson
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Diagnostic Cytopathology, Vol 8, No 6
JD, Winsten JA, eds. Origins of human cancer. New York: Cold Spring Harbor Laboratory, 1977:1765-1784. 6. Hillerdal G. Rounded atelectasis. Clinical experience with 74 patients. Chest 1989;95:836-841. 7. Stancato-Pasik A, Mendelson DS, Marom Z. Rounded atelectasis caused by histoplasmosis. AJR 1990;155(2):275-276. 8. Menzies R, Fraser R. Rounded atelectasis: Pathologic and pathogenetic features. Am J Surg Pathol 1987;11:674681.
9. Dernevik L, Gatzinsky P. Pathogenesis of shrinking pleuritis with atelectasis-"rounded atelectasis." Eur J Respir Dis 1987;71:244 249. 110. Case Records of the Massachusetts General Hospital (Case 241983). N Engl J Med 1983;308(24):1466-1472.
