| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Case Report |
1 Department of Diagnostic Imaging, The Ottawa Hospital, University of Ottawa,
1053 Carling Ave., Ottawa, Ontario K1Y 4E9, Canada.
2 Department of Laboratory Medicine, The Ottawa Hospital, University of Ottawa,
Ottawa, Ontario K1Y 4E9, Canada.
3 Division of Respirology, London Health Sciences Centre-Victoria Campus, 375
South St., London, Ontario N6A 4G5, Canada.
4 Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin
St., Ottawa, Ontario K1Y 4W7, Canada.
Received November 27, 2000;
accepted after revision November 21, 2001.
Address correspondence to C. J. Dennie.
Introduction
 Top Introduction Case ReportsDiscussionReferences |
|---|
We present two cases of intimal sarcoma of the pulmonary arteries with clinical and CT findings identical to those of chronic thromboembolic pulmonary hypertension, including a mosaic pattern of lung attenuation.
|
TopIntroductionCase ReportsDiscussionReferences |
|---|
A chest radiograph showed enlargement of the right ventricle and left pulmonary artery. A transthoracic echocardiogram showed severe pulmonary artery hypertension. Contrast-enhanced helical CT of the chest revealed filling defects in the right and left pulmonary arteries (Fig. 1A) as well as in several segmental and subsegmental arteries (Fig. 1B) and rapid tapering of the right interlobar artery. High-resolution CT of the thorax depicted a mosaic pattern of lung attenuation consistent with chronic thromboembolic pulmonary hypertension (Fig. 1C). No pulmonary nodules were seen.
|
|
|
On admission, the patient could not lie supine, and obtaining a pulmonary angiogram was not possible. She was taken to the operating room for pulmonary thromboendarterectomy because she was developing hemodynamic compromise. Endarterectomy was performed under deep hypothermic circulatory arrest, using standard techniques [4]. Both pulmonary arteries were explored, and extensive specimens were removed. Several attempts were made to discontinue cardiopulmonary bypass, but right heart failure developed due to severe pulmonary hypertension. Extracorporeal membrane oxygenation was initiated, and a pulmonary angiogram was obtained revealing persistent obstruction of the right upper and middle lobe arteries. The patient was returned to the operating room, where the right pulmonary artery was reexplored, but no further material could be removed.
When the final pathologic results revealed intimal sarcoma of the pulmonary artery as the cause of this patient's pulmonary artery hypertension, extracorporeal membrane oxygenation was discontinued and the patient died.
The second patient was a 64-year-old woman with a history of breast carcinoma and chest wall radiation, who presented with a 4-month history of progressive dyspnea and atrial fibrillation. Contrast-enhanced helical CT of the chest showed filling defects in the pulmonary artery circulation (Figs. 2A and 2B). High-resolution CT revealed a subtle mosaic pattern of perfusion that was most evident in the right upper lobe, suggesting the diagnosis of chronic thromboembolic pulmonary hypertension (Fig. 2C). Although the radiologic findings were similar to those of the first patient with intimal sarcoma, this diagnosis was not considered preoperatively.
|
|
|
The patient was taken to the operating theater for pulmonary thromboendarterectomy. However, the gross nature of the resected specimen was suggestive of a malignant tumor rather than of an endothelial blood clot. Despite this complication, the patient was successfully weaned from cardiopulmonary bypass and recovered uneventfully.
The surgical specimens consisted of soft tan branching masses that resembled casts of pulmonary arteries. Specimens from both patients were similar to other pulmonary artery thromboendarterectomy specimens but had mucoid regions, and in the second case, firm cartilaginous areas. Microscopic examination revealed the specimens to be poorly differentiated intimal sarcoma of the pulmonary artery. The entire cast of specimens was composed of tumor with extensive arborization. The tumors were mixed with small amounts of organizing thrombus, but the thrombotic component was not prominent. In the second patient, the firm areas were chondrosarcomatous differentiation of malignant cartilage tissues.
|
TopIntroductionCase ReportsDiscussionReferences |
|---|
Pulmonary artery sarcomas generally arise from the intimal layer of the right, left, and main pulmonary arteries and extend as polypoid masses into the small pulmonary arteries [5, 6]. Less commonly, they grow in a retrograde fashion to involve the pulmonary valve and right ventricle [5, 6]. In approximately 50% of patients, the tumors spread transmurally into adjacent lung, bronchial wall, or lymph nodes, and extension to myocardium and mediastinum has also been described. The most common site of distant metastases is the lung [5].
The radiologic findings of pulmonary artery sarcoma depend on the size of the tumor. If the tumor is large enough to distend an artery but remains intraluminal, it will present as a unilateral hilar mass that may project into pulmonary parenchyma in an arterial distribution. There may be associated distal oligemia. If the mass extends transmurally into adjacent lung, it mimics bronchogenic carcinoma. If the mass is intraluminal and does not distend the artery, findings on the chest radiograph may be normal [7].
On pulmonary angiography, the distinction between tumor and thrombus may be possible when the polypoid intraluminal filling defects move with the cardiac cycle [5]. Otherwise, the findings are nonspecific and mimic pulmonary thromboemboli.
Contrast-enhanced CT shows filling defects in the pulmonary arteries that are indistinguishable from acute or chronic pulmonary emboli. On high-resolution CT, our patient presented with a mosaic pattern of lung attenuation that was indistinguishable from chronic thromboembolic pulmonary artery hypertension. We postulate that this was due to direct tumor growth into small pulmonary arteries or tumor emboli occluding small peripheral vessels. This pattern is a newly described vascular cause of inhomogeneous lung density.
Gadolinium-enhanced MR imaging of the pulmonary arteries is diagnostic of tumor rather than of blood clot if the diagnosis is considered preoperatively, because vascularized tumor enhances, whereas nonvascularized intraluminal blood clot does not [8].
In summary, intimal sarcoma of the pulmonary artery should be considered in the differential diagnosis of chronic thromboembolic hypertension. Contrast-enhanced helical CT findings of filling defects in pulmonary arteries and high-resolution CT findings of a mosaic pattern of lung attenuation can resemble chronic thromboembolic hypertension. Distention of pulmonary arteries by filling defects should alert the radiologist to the possibility of tumor rather than blood clot and should prompt gadolinium-enhanced MR imaging.
Furthermore, if the diagnosis of intimal sarcoma is not made before surgery, it should be considered in patients who have undergone pulmonary thromboendarterectomy in whom pulmonary hypertension persists, particularly when the surgeon believes that clot removal has been successful.
|
TopIntroductionCase ReportsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  S. H. Blackmon, D. C. Rice, A. M. Correa, R. Mehran, J. B. Putnam, W. R. Smythe, J.-C. Walkes, G. L. Walsh, C. Moran, H. Singh, et al. Management of Primary Pulmonary Artery Sarcomas. Ann. Thorac. Surg., March 1, 2009; 87(3): 977 - 984. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
