Primary and Secondary Pulmonary Artery Neoplasia ~imicking Acute Pulmonary Embolism 1
Diagnostic Radiology
Harold E. Olsson, M.D., Robert M. Spitzer, M.D., and Walter F. Erston, M.D.2 Two cases of rare pulmonary neoplastic lesions (primary pulmonary artery sarcoma and pulmonary carcinosarcoma) directly involving the pulmonary artery and presenting with findings mimicking acute pulmonary embolism are discussed. Although this represents an unusual presentation for these two lesions, they should be included in the differential diagnosis of acute pulmonary embolism in patients presenting with somewhat atypical clinical, isotopic, and radiological features. Serial lung scans followed by angiography will prove useful in arriving at the correct diagnosis. INDEX TERMS: Embolism, pulmonary. Lung Neoplasms, diagnosis • Lungs, radionuclide studies. Neoplasms, radionuclide diagnosis. Pulmonary angiography, indications • Pulmonary arteries, abnormalities • Sarcoma Radiology 118:49-53, January 1976
monary neoplastic lesions presenting as acute pulmonary embolism.
well established that primary malignant pulmonary lesions can result in alterations of pulmonary blood flow and will seldom resemble acute pulmonary embolism. This is due to the slow evolution of symptoms, the presence of a mass in the lung or mediastinum, and the lack of an intraluminal mass at angiography. Rarer forms of pulmonary neoplasia directly involving the pulmonary artery may mimic the symptoms and angiographic findings of pulmonary embolism. The purpose of this paper is to report 2 cases of rare pulT HAS BEEN
I
CASE REPORTS CASE I (J. v.): A 52-year-old man was admitted with right pleuritic chest pain and tachypnea of sudden onset. On physical examination, dullness to percussion and fine rales were present at the right base. Arterial blood gases (on room air) were pC0 2 29 mm Hg and p02 4~ mm Hg. Chest radiography (Fig. 1, A) revealed bilateral lower-lobe alveolar
Fig. 1. CASE I. A. Supine admission chest radiograph revealing bilateral lower lobe alveolar densities and partial atelectasis on the right associated with elevation of the right hemidiaphragm. . B. Initial lung scan shows absent perfusion of the right middle and lower lobes. A small area of perfused right upper lobe is seen. The perfusion of the left lung is normal. C. Pulmonary angiography demonstrates a large lobulated mural mass filling the right pulmonary artery and occluding 'the artery to the right lower lobe.
1 From the Department of Radiology (H. E. O. and R. M. S.), Rochester General Hospital, Rochester, N. Y. Accepted for publication in August 1975. 2 Current Address: Department of Radiology, Arnot-Ogden Memorial Hospital, Elmira, N. Y. elk
49
I
II
A,l
Fig. 2. CASE I. A. Repeat lung scan on the 16th hospital day shows progression to absent perfusion of the right lung. No perfusion defects are present on the left. B. A repeat pulmonary angiogram on the seventeenth hospital day demonstrates enlargement of the lobulated mass which now completely occludes the right pulmonary artery and extends into the outflow tract of the pulmonary trunk.
Fig. 3. CASE II. A. Chest radiograph at admission shows peripheral alveolar densities in the right upper, middle, and lower lobes with a small right pleural effusion. Relative oligemia of the right upper lobe is noted. B. Lung scan shows total absence of perfusion of the right lung with normal perfusion of the left. C. Composite of bilateral selective pulmonary angiography. A large mass at the bifurcation of the right pulmonary artery is noted to partially occlude the right lower lobe artery and cornpletely occlude the arteries to the upper and middle lobes.
B 50
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Diagnostic Radiology
Fig. 4. CASE II. The discharge chest radiograph (at initial admission) documents interval clearing of the right upper lobe alveolar density. Residual densities in the right middle and lower lobes indicate more slowly resolving infarcts. Right lung oligemia and elevation of the right hemidiaphragm persists. A small density is present lateral to the right hilus. Fig. 5. CASE II. This readmisslon chest radiograph shows enlargement of the right hilar mass and a right lower lobe mass during the twomonth interval since Figure 4.
densities with partial atelectasis. A lung scan (Fig. 1, B) revealed reduced perfusion on the right. The pulmonary angiogram (Fig. 1, C) demonstrated an intraluminal mass nearly Q,Ccluding the right p.ulmonary artery and completely occluding the right lower lobe artery. The lower extremity phlebogram was negative, and anticoagulant therapy was initiated. A repeat lung scan (Fig. 2, A) on the 16th hospital day showed total absence of perfusion on the right side. A pulmonary angiogram (Fig. 2, B) showed total occlusion of the right pulmonary artery. Thoracotomy revealed a primary pulmonary artery sarcoma arising in the main pulmonary artery and extending into the right pulmonary artery. Arrhythmias were encountered postoperatively and the patient died on the tenth postoperative day. Autopsy revealed residual tumor in the right upper, middle, and lower lobe pulmonary arteries. The tumor was confined to the vascular system and at one point only was it noted to have invaded the periadventitial tissues. CASE II (A. D.): A 35-year-old man was admitted with severe right pleuritic chest pain and hemoptysis of sudden onset. During the previous 1Y2 years he had had intermittent chest pain which initiated multiple emergency room visits, but no diagnosis was established. On physical examination, decreased breath sounds were found in the right hemithorax. Arterial blood gases (on room air) were pC02 25 mm Hg and p02 51 mm Hg. Chest radiography (Fig. 3, A) revealed a right upper, middle, and lower lobe alveolar density with a small pleural effusion. The lung scan (Fig. 3, B) showed no perfusion on the right. Pulmonary angiography (Fig. 3, C) showed an occ!uding intraluminal mass on the right while a lower extremity phlebogram was negative. Anticoagulant therapy was initiated and the patient was discharged with radiographic evidence of interval improvement (Fig. 4). Continued severe intermittent chest pain led to several interval emergency room visits with a second hospital admission two months after discharge. A chest radiograph at that time (Fig. 5) showed a right hilar and right lower lobe mass. A diagnosis of "probable sarcoma" was established by open biopsy. He died 4 months from the
time of correct diagnosis. On autopsy, extensive pulmonary carcinosarcoma was found with intraluminal tumor occupying the right pulmonary artery and extending into the proximal portion of the left pulmonary artery. No tumor was present in the bronchi.
DISCUSSION
The alteration of pulmonary blood flow by malignant lesions has been thoroughly investigated in patients with bronchogenic carcinoma. Arterial narrowing and occlusion have been documented in patients with large mass lesions (1, 2). In addition, reduced peripheral pulmonary artery pulsations (3), altered perfusion lung scans (4), and diffusely slowed flow at angiography (5) are well established findings in patients without direct carcinomatous arterial involvement. .Because of the absence of arterial occlusions or an intraluminal mass in most cases of bronchogenic carcinoma (1), it is seldom confused with acute pulmonary embolism at angiography. In addition, because of the presence of a parenchymal mass and the absence of an acute presentation, it will seldom be necessary to use angiography to exclude acute pulmonary ernbollsrn. Primary pulmonary artery sarcoma, on the other hand, might be expected to mimic acute pulmonary embolism. It is a rare pulmonary neoplastic lesion typically arising from the main pulmonary artery (6, 7). Pulmonary infarcts (7, 8) due to tumor emboli or small thrombi arising on the mass might be expected to lead to symptoms of acute embolism; indeed, cough, dyspnea, chest pain, and hemoptysis are frequent symptoms (6, 9, 10), although the predominant clinical presentation is pro-
52
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OLSSON AND OTHERS
gressive right heart failure (7, 11, 12). The clinical symptoms of acute pulmonary embolism occur in patients with primary pulmonary artery sarcoma, but the clinical presentation of this tumor more closely simulates chronic or recurrent thromboembolism (13). In addition, the presence of a hilar mass, the most frequent radiographic finding (6), and the usually more gradual progression of symptoms will seldom result in primary pulmonary artery sarcoma being confused with acute pulmonary embolism. A review of the literature indicates that only 4 previously reported patients were mistakenly diagnosed as having thromboembolism (7, 9, 11, 14). In each case, the clinical course of the patient more closely simulated chronic or recurrent thromboembolism with the development of right heart failure. To these, we add a case of primary pulmonary artery sarcoma presenting with signs and symptoms resembling acute pulmonary embolism. Pulmonary carcinosarcoma would not ordinarily be expected to be confused with acute pulmonary embolism. It is an uncommon pulmonary neoplasm possessing both carcinomatous parenchyma and sarcomatous stroma. Two types are known (15). The central type is a pedunculated endobronchlal lesion presenting with symptoms of bronchial obstruction; The less frequent peripheral type tends to spread more rapidly, with a propensity to invade the chest wall, mediastinum, and vascular structures (16, 17). CASE II is an example of the peripheral form of carcinosarcoma arising adjacent to the right hilus with -early invasion of the pulmonary artery. Although this lesion arose centrally, the absence of an endobronchial lesion at autopsy, the presence of vascular invasion, and the rapid clinical deterioration are features of the peripheral form of carcinosarcoma. The most frequently reported clinical findings in patients with the peripheral type of carcinosarcoma are weight loss, chest pain, and evidence of distant metastases (17, 18). These condltions have been typically diagnosed as bronchogenic carcinoma prior to biopsy, even though bronchoscopy and cytology results are negative (18). No patient with carcinosarcoma has previously been reported with a clinical presentation resembling acute pulmonary embolism. In each of our cases a diagnosis of pulmonary embolism was made on the basis of clinical, radiological, and isotopic data. The sudden onset of pleuritic chest pain, alveolar parenchymal densities, low P02, large perfusion defects, and intraluminal masses at angiography were consistent with a diagnosis of pulmonary thromboembolism. In this setting, and in the absence of a hilar or peripheral mass, the diagnosis of a neoplasfic vascular occlusion represents a difficult clinical and radiological problem. ' The 2 cases described in this report illustrate features which should prove useful in establishing the correct diagnosis. The absence of predisposing factors for massive embolization in these two active men (19, 20) and the persistence of symptoms on adequate antico-
January 1976
agulant therapy are atypical of pulmonary embolism. The unilateral distribution of massive perfusion defects (Fig. 2, A) is unusual and is found in less than 1 % of patients with documented pulmonary embolic disease (21, 22). In addition, although lobulated intraluminal filling defects are well recognized in pulmonary embolism (23), incompletely outlined marginal lesions in the most proximal portions of the pulmonary arterial tree (Fig. 1, C) are uncommon (20). For patients presenting with these features it is recommended that serial perfusion scans be obtained at weekly or biweekly intervals in order to document resolution of thromboembolism (24-26). In patients under the age of 60 (25) and without chronic obstructive pulmonary disease (24), documentation of interval improvement or a changing pattern of perfusion defects (26, 27) would strengthen the diagnosis of pulmonary thromboembolism. Interval progression of the perfusion defects in spite of adequate anticoagulation should raise the suspicion of a nonembolic cause of symptoms and warrants further investigation by angiography.
SUMMARY Primary pulmonary artery sarcoma and pulmonary carcinosarcoma should be included in the differential diagnosis of acute and chronic pulmonary embolism, because they can present with similar clinical, isotopic, and radiographic features. Although rare, these neoplastic lesions should be considered in those patients with somewhat atypical findings of pulmonary thromboembolism. Serial perfusion scans in this group of patients will differentiate those needing further study and may prove useful in arriving at the correct diagnosis.
REFERENCES 1. Ballantyne AJ, Clage~ QT, McDonald JR: Vascular invasion in bronchogenic carcinoma. Thorax (London) 12:294-299, Dec 1957 2. Dotter CT, Steinberg I, Holman CW: Lung cancer operability. Am J RoentgenoI64:222-237, Aug 1950 3. Sutherland GR, Leask E, Samuel E: Pulmonary vascular and ventilatory changes in bronchial carcinoma studied by flurodensitometry. Clin RadioI19:269-277, Jul 1968 4. Wagner HN Jr, Lopez-Majano V, Tow DE, et al: Radioisotope scanning of lungs in early diagnosis of bronchogenic carcinoma. Lancet 1:344, 13 Feb 1965 5. Bookstein JJ, Silver TM: The angiographic differential diagnosis of acute pulmonary embolism. Radiology 110:25-33, Jan 1974 6. Moffat RE, Chang CH, Slaven JE: Roentgen considerations in primary pulmonary artery sarcoma. Radiology 104:283-288, Aug 1972 7. Munk J, Griffel B, Kogan J: Primary mesenchymoma of the pulmonary artery: radiological features. Br J Radiol 38: 104- 111, Feb 1965 8. Ali MY, Lee GS: Sarcoma of the pulmonary artery. Cancer 17:1220-1224, Sep 1964 9. Elphinstone RH, Spector RG: Sarcoma of the pulmonary artery. Thorax 14:333-340, Dec 1959 1O. S~thi GK, Slaven JE, Kepes JJ, et al: Primary sarcoma of the pulmonary artery. J Thorac Cardiovasc Surg '83:587-593, Apr 1972 11. Friedman HM, Smith CK: Leiomyosarcoma of the pulmonary artery. JAMA 203:809, Feb 1968
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PULMONARY ARTERY NEOPLASIA
12. Thijs lG, Kroon TAJ, Van Leeuwen TM: leiomyosarcoma of the pulmonary trunk associated with pericardial effusion. Thorax 29:490-494,JuI1974 13. Owen WR, Thomas WA, Castleman B, et al: Unrecognized emboli to the lungs with subsequent cor pulmonale. N Engl J Med 249:919-926,3 Dec 1953 14. Case Records of the Massachusetts General Hospital: No. 49-1966. N Engl J Med 275: 1063- 1071, Nov 1966 15. Razzuk MA, Urschel HC Jr, Race GJ, et al: Carcinosarcoma of the lung. Report of two cases and review of literature. J Thorae Cardiovasc Surg 61:541-546, Apr 1971 16. Jenkins BJ: Carcinosarcoma of the lung. Report of a case and review of the literature. J Thorac Cardiovasc Surg 55:657-662, May 1968 17. Moore TC: Carcinosarcoma of the lung. Surgery 50:886893, Dec 1961 18. Kakos GS, Williams TE Jr, Assor D, et al: Pulmonary carcinosarcoma. Etiologic, therapeutic and prognostic considerations. J Thorac Cardiovasc Surg 61:777-783, May 1971 19. Sasahara AA, Cannilla JE, Morse RL, et al: Clinical and physiologic studies in pulmonary thromboembolism. Am J Cardiol 20:10-20,JuI1967 20. Sasahara AA, Hyers TM, Cole C, et al, eds: The urokinase pulmonary embolism trial. A national cooperative study. Circulation 47 (Suppl 2):1-1 08, Apr 1973
53
Diagnostic Radiology
21. Gilday Dl, Poulose KP, Deland FH: Accuracy of detection of pulmonary embolism by lung scanning correlated with pulmonary angiography. Am J Roentgenol115:732-738, Aug 1972 22. White RI Jr, James AE Jr, Wagner HN Jr: The significance of unilateral absence of pulmonary artery perfusion by lung scanning. Am J Roentgenol111:501-509, Mar 1971 23. Dalen JE, Brooks HL, Johnson LW, et al: Pulmonaryangiography in acute pulmonary embolism: indications, techniques, and results in 367 patients. Am HeartJ 81:175-185, Feb 1971 24. Secker Walker RH, Jackson JA, Goodwin J: Resolution of pulmonary embolism. Br Med J 4: 135-139, Oct 1970 25. Winebright JW, Gerdes AJ, Nelp WB: Restoration of blood flow after pulmonary embolism. Arch Intern Med (Chicago) 125: 241-247, Feb 1970 26. Tow DE, Wagner HN Jr: Recovery of pulmonary arterial blood flow in patients with pulmonary embolism. N Engl J Med 276: 1053-1059, 11 May 1967 27. McNeil BJ, Holman BL, Adelstein J: The scintigraphic definition of pulmonary embolism. JAMA 227:753-756, 18 Feb 1974
Department of Radiology Rochester General Hospital 1425 Portland Ave. Rochester, N. Y. 14621
Diagnostic Radiology
Harold E. Olsson, M.D., Robert M. Spitzer, M.D., and Walter F. Erston, M.D.2 Two cases of rare pulmonary neoplastic lesions (primary pulmonary artery sarcoma and pulmonary carcinosarcoma) directly involving the pulmonary artery and presenting with findings mimicking acute pulmonary embolism are discussed. Although this represents an unusual presentation for these two lesions, they should be included in the differential diagnosis of acute pulmonary embolism in patients presenting with somewhat atypical clinical, isotopic, and radiological features. Serial lung scans followed by angiography will prove useful in arriving at the correct diagnosis. INDEX TERMS: Embolism, pulmonary. Lung Neoplasms, diagnosis • Lungs, radionuclide studies. Neoplasms, radionuclide diagnosis. Pulmonary angiography, indications • Pulmonary arteries, abnormalities • Sarcoma Radiology 118:49-53, January 1976
monary neoplastic lesions presenting as acute pulmonary embolism.
well established that primary malignant pulmonary lesions can result in alterations of pulmonary blood flow and will seldom resemble acute pulmonary embolism. This is due to the slow evolution of symptoms, the presence of a mass in the lung or mediastinum, and the lack of an intraluminal mass at angiography. Rarer forms of pulmonary neoplasia directly involving the pulmonary artery may mimic the symptoms and angiographic findings of pulmonary embolism. The purpose of this paper is to report 2 cases of rare pulT HAS BEEN
I
CASE REPORTS CASE I (J. v.): A 52-year-old man was admitted with right pleuritic chest pain and tachypnea of sudden onset. On physical examination, dullness to percussion and fine rales were present at the right base. Arterial blood gases (on room air) were pC0 2 29 mm Hg and p02 4~ mm Hg. Chest radiography (Fig. 1, A) revealed bilateral lower-lobe alveolar
Fig. 1. CASE I. A. Supine admission chest radiograph revealing bilateral lower lobe alveolar densities and partial atelectasis on the right associated with elevation of the right hemidiaphragm. . B. Initial lung scan shows absent perfusion of the right middle and lower lobes. A small area of perfused right upper lobe is seen. The perfusion of the left lung is normal. C. Pulmonary angiography demonstrates a large lobulated mural mass filling the right pulmonary artery and occluding 'the artery to the right lower lobe.
1 From the Department of Radiology (H. E. O. and R. M. S.), Rochester General Hospital, Rochester, N. Y. Accepted for publication in August 1975. 2 Current Address: Department of Radiology, Arnot-Ogden Memorial Hospital, Elmira, N. Y. elk
49
I
II
A,l
Fig. 2. CASE I. A. Repeat lung scan on the 16th hospital day shows progression to absent perfusion of the right lung. No perfusion defects are present on the left. B. A repeat pulmonary angiogram on the seventeenth hospital day demonstrates enlargement of the lobulated mass which now completely occludes the right pulmonary artery and extends into the outflow tract of the pulmonary trunk.
Fig. 3. CASE II. A. Chest radiograph at admission shows peripheral alveolar densities in the right upper, middle, and lower lobes with a small right pleural effusion. Relative oligemia of the right upper lobe is noted. B. Lung scan shows total absence of perfusion of the right lung with normal perfusion of the left. C. Composite of bilateral selective pulmonary angiography. A large mass at the bifurcation of the right pulmonary artery is noted to partially occlude the right lower lobe artery and cornpletely occlude the arteries to the upper and middle lobes.
B 50
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Diagnostic Radiology
Fig. 4. CASE II. The discharge chest radiograph (at initial admission) documents interval clearing of the right upper lobe alveolar density. Residual densities in the right middle and lower lobes indicate more slowly resolving infarcts. Right lung oligemia and elevation of the right hemidiaphragm persists. A small density is present lateral to the right hilus. Fig. 5. CASE II. This readmisslon chest radiograph shows enlargement of the right hilar mass and a right lower lobe mass during the twomonth interval since Figure 4.
densities with partial atelectasis. A lung scan (Fig. 1, B) revealed reduced perfusion on the right. The pulmonary angiogram (Fig. 1, C) demonstrated an intraluminal mass nearly Q,Ccluding the right p.ulmonary artery and completely occluding the right lower lobe artery. The lower extremity phlebogram was negative, and anticoagulant therapy was initiated. A repeat lung scan (Fig. 2, A) on the 16th hospital day showed total absence of perfusion on the right side. A pulmonary angiogram (Fig. 2, B) showed total occlusion of the right pulmonary artery. Thoracotomy revealed a primary pulmonary artery sarcoma arising in the main pulmonary artery and extending into the right pulmonary artery. Arrhythmias were encountered postoperatively and the patient died on the tenth postoperative day. Autopsy revealed residual tumor in the right upper, middle, and lower lobe pulmonary arteries. The tumor was confined to the vascular system and at one point only was it noted to have invaded the periadventitial tissues. CASE II (A. D.): A 35-year-old man was admitted with severe right pleuritic chest pain and hemoptysis of sudden onset. During the previous 1Y2 years he had had intermittent chest pain which initiated multiple emergency room visits, but no diagnosis was established. On physical examination, decreased breath sounds were found in the right hemithorax. Arterial blood gases (on room air) were pC02 25 mm Hg and p02 51 mm Hg. Chest radiography (Fig. 3, A) revealed a right upper, middle, and lower lobe alveolar density with a small pleural effusion. The lung scan (Fig. 3, B) showed no perfusion on the right. Pulmonary angiography (Fig. 3, C) showed an occ!uding intraluminal mass on the right while a lower extremity phlebogram was negative. Anticoagulant therapy was initiated and the patient was discharged with radiographic evidence of interval improvement (Fig. 4). Continued severe intermittent chest pain led to several interval emergency room visits with a second hospital admission two months after discharge. A chest radiograph at that time (Fig. 5) showed a right hilar and right lower lobe mass. A diagnosis of "probable sarcoma" was established by open biopsy. He died 4 months from the
time of correct diagnosis. On autopsy, extensive pulmonary carcinosarcoma was found with intraluminal tumor occupying the right pulmonary artery and extending into the proximal portion of the left pulmonary artery. No tumor was present in the bronchi.
DISCUSSION
The alteration of pulmonary blood flow by malignant lesions has been thoroughly investigated in patients with bronchogenic carcinoma. Arterial narrowing and occlusion have been documented in patients with large mass lesions (1, 2). In addition, reduced peripheral pulmonary artery pulsations (3), altered perfusion lung scans (4), and diffusely slowed flow at angiography (5) are well established findings in patients without direct carcinomatous arterial involvement. .Because of the absence of arterial occlusions or an intraluminal mass in most cases of bronchogenic carcinoma (1), it is seldom confused with acute pulmonary embolism at angiography. In addition, because of the presence of a parenchymal mass and the absence of an acute presentation, it will seldom be necessary to use angiography to exclude acute pulmonary ernbollsrn. Primary pulmonary artery sarcoma, on the other hand, might be expected to mimic acute pulmonary embolism. It is a rare pulmonary neoplastic lesion typically arising from the main pulmonary artery (6, 7). Pulmonary infarcts (7, 8) due to tumor emboli or small thrombi arising on the mass might be expected to lead to symptoms of acute embolism; indeed, cough, dyspnea, chest pain, and hemoptysis are frequent symptoms (6, 9, 10), although the predominant clinical presentation is pro-
52
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E.
OLSSON AND OTHERS
gressive right heart failure (7, 11, 12). The clinical symptoms of acute pulmonary embolism occur in patients with primary pulmonary artery sarcoma, but the clinical presentation of this tumor more closely simulates chronic or recurrent thromboembolism (13). In addition, the presence of a hilar mass, the most frequent radiographic finding (6), and the usually more gradual progression of symptoms will seldom result in primary pulmonary artery sarcoma being confused with acute pulmonary embolism. A review of the literature indicates that only 4 previously reported patients were mistakenly diagnosed as having thromboembolism (7, 9, 11, 14). In each case, the clinical course of the patient more closely simulated chronic or recurrent thromboembolism with the development of right heart failure. To these, we add a case of primary pulmonary artery sarcoma presenting with signs and symptoms resembling acute pulmonary embolism. Pulmonary carcinosarcoma would not ordinarily be expected to be confused with acute pulmonary embolism. It is an uncommon pulmonary neoplasm possessing both carcinomatous parenchyma and sarcomatous stroma. Two types are known (15). The central type is a pedunculated endobronchlal lesion presenting with symptoms of bronchial obstruction; The less frequent peripheral type tends to spread more rapidly, with a propensity to invade the chest wall, mediastinum, and vascular structures (16, 17). CASE II is an example of the peripheral form of carcinosarcoma arising adjacent to the right hilus with -early invasion of the pulmonary artery. Although this lesion arose centrally, the absence of an endobronchial lesion at autopsy, the presence of vascular invasion, and the rapid clinical deterioration are features of the peripheral form of carcinosarcoma. The most frequently reported clinical findings in patients with the peripheral type of carcinosarcoma are weight loss, chest pain, and evidence of distant metastases (17, 18). These condltions have been typically diagnosed as bronchogenic carcinoma prior to biopsy, even though bronchoscopy and cytology results are negative (18). No patient with carcinosarcoma has previously been reported with a clinical presentation resembling acute pulmonary embolism. In each of our cases a diagnosis of pulmonary embolism was made on the basis of clinical, radiological, and isotopic data. The sudden onset of pleuritic chest pain, alveolar parenchymal densities, low P02, large perfusion defects, and intraluminal masses at angiography were consistent with a diagnosis of pulmonary thromboembolism. In this setting, and in the absence of a hilar or peripheral mass, the diagnosis of a neoplasfic vascular occlusion represents a difficult clinical and radiological problem. ' The 2 cases described in this report illustrate features which should prove useful in establishing the correct diagnosis. The absence of predisposing factors for massive embolization in these two active men (19, 20) and the persistence of symptoms on adequate antico-
January 1976
agulant therapy are atypical of pulmonary embolism. The unilateral distribution of massive perfusion defects (Fig. 2, A) is unusual and is found in less than 1 % of patients with documented pulmonary embolic disease (21, 22). In addition, although lobulated intraluminal filling defects are well recognized in pulmonary embolism (23), incompletely outlined marginal lesions in the most proximal portions of the pulmonary arterial tree (Fig. 1, C) are uncommon (20). For patients presenting with these features it is recommended that serial perfusion scans be obtained at weekly or biweekly intervals in order to document resolution of thromboembolism (24-26). In patients under the age of 60 (25) and without chronic obstructive pulmonary disease (24), documentation of interval improvement or a changing pattern of perfusion defects (26, 27) would strengthen the diagnosis of pulmonary thromboembolism. Interval progression of the perfusion defects in spite of adequate anticoagulation should raise the suspicion of a nonembolic cause of symptoms and warrants further investigation by angiography.
SUMMARY Primary pulmonary artery sarcoma and pulmonary carcinosarcoma should be included in the differential diagnosis of acute and chronic pulmonary embolism, because they can present with similar clinical, isotopic, and radiographic features. Although rare, these neoplastic lesions should be considered in those patients with somewhat atypical findings of pulmonary thromboembolism. Serial perfusion scans in this group of patients will differentiate those needing further study and may prove useful in arriving at the correct diagnosis.
REFERENCES 1. Ballantyne AJ, Clage~ QT, McDonald JR: Vascular invasion in bronchogenic carcinoma. Thorax (London) 12:294-299, Dec 1957 2. Dotter CT, Steinberg I, Holman CW: Lung cancer operability. Am J RoentgenoI64:222-237, Aug 1950 3. Sutherland GR, Leask E, Samuel E: Pulmonary vascular and ventilatory changes in bronchial carcinoma studied by flurodensitometry. Clin RadioI19:269-277, Jul 1968 4. Wagner HN Jr, Lopez-Majano V, Tow DE, et al: Radioisotope scanning of lungs in early diagnosis of bronchogenic carcinoma. Lancet 1:344, 13 Feb 1965 5. Bookstein JJ, Silver TM: The angiographic differential diagnosis of acute pulmonary embolism. Radiology 110:25-33, Jan 1974 6. Moffat RE, Chang CH, Slaven JE: Roentgen considerations in primary pulmonary artery sarcoma. Radiology 104:283-288, Aug 1972 7. Munk J, Griffel B, Kogan J: Primary mesenchymoma of the pulmonary artery: radiological features. Br J Radiol 38: 104- 111, Feb 1965 8. Ali MY, Lee GS: Sarcoma of the pulmonary artery. Cancer 17:1220-1224, Sep 1964 9. Elphinstone RH, Spector RG: Sarcoma of the pulmonary artery. Thorax 14:333-340, Dec 1959 1O. S~thi GK, Slaven JE, Kepes JJ, et al: Primary sarcoma of the pulmonary artery. J Thorac Cardiovasc Surg '83:587-593, Apr 1972 11. Friedman HM, Smith CK: Leiomyosarcoma of the pulmonary artery. JAMA 203:809, Feb 1968
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PULMONARY ARTERY NEOPLASIA
12. Thijs lG, Kroon TAJ, Van Leeuwen TM: leiomyosarcoma of the pulmonary trunk associated with pericardial effusion. Thorax 29:490-494,JuI1974 13. Owen WR, Thomas WA, Castleman B, et al: Unrecognized emboli to the lungs with subsequent cor pulmonale. N Engl J Med 249:919-926,3 Dec 1953 14. Case Records of the Massachusetts General Hospital: No. 49-1966. N Engl J Med 275: 1063- 1071, Nov 1966 15. Razzuk MA, Urschel HC Jr, Race GJ, et al: Carcinosarcoma of the lung. Report of two cases and review of literature. J Thorae Cardiovasc Surg 61:541-546, Apr 1971 16. Jenkins BJ: Carcinosarcoma of the lung. Report of a case and review of the literature. J Thorac Cardiovasc Surg 55:657-662, May 1968 17. Moore TC: Carcinosarcoma of the lung. Surgery 50:886893, Dec 1961 18. Kakos GS, Williams TE Jr, Assor D, et al: Pulmonary carcinosarcoma. Etiologic, therapeutic and prognostic considerations. J Thorac Cardiovasc Surg 61:777-783, May 1971 19. Sasahara AA, Cannilla JE, Morse RL, et al: Clinical and physiologic studies in pulmonary thromboembolism. Am J Cardiol 20:10-20,JuI1967 20. Sasahara AA, Hyers TM, Cole C, et al, eds: The urokinase pulmonary embolism trial. A national cooperative study. Circulation 47 (Suppl 2):1-1 08, Apr 1973
53
Diagnostic Radiology
21. Gilday Dl, Poulose KP, Deland FH: Accuracy of detection of pulmonary embolism by lung scanning correlated with pulmonary angiography. Am J Roentgenol115:732-738, Aug 1972 22. White RI Jr, James AE Jr, Wagner HN Jr: The significance of unilateral absence of pulmonary artery perfusion by lung scanning. Am J Roentgenol111:501-509, Mar 1971 23. Dalen JE, Brooks HL, Johnson LW, et al: Pulmonaryangiography in acute pulmonary embolism: indications, techniques, and results in 367 patients. Am HeartJ 81:175-185, Feb 1971 24. Secker Walker RH, Jackson JA, Goodwin J: Resolution of pulmonary embolism. Br Med J 4: 135-139, Oct 1970 25. Winebright JW, Gerdes AJ, Nelp WB: Restoration of blood flow after pulmonary embolism. Arch Intern Med (Chicago) 125: 241-247, Feb 1970 26. Tow DE, Wagner HN Jr: Recovery of pulmonary arterial blood flow in patients with pulmonary embolism. N Engl J Med 276: 1053-1059, 11 May 1967 27. McNeil BJ, Holman BL, Adelstein J: The scintigraphic definition of pulmonary embolism. JAMA 227:753-756, 18 Feb 1974
Department of Radiology Rochester General Hospital 1425 Portland Ave. Rochester, N. Y. 14621
