A 55-yr-old male presented with acute chest pain, dyspnea, and hypotension on December 8, 2009. The patient has been followed without any medications for incidentally detected asymptomatic SVC aneurysm for last 2 yr (, and the size of the SVC aneurysm did not change (). Chest radiography at admission showed marked widening of the right middle mediastinum due to abnormal soft-tissue density suggesting the rapid expansion of previously noted SVC aneurysm (). Echocardiography revealed marked enlargement and hypokinesia of the right ventricle (RV) with moderate pulmonary hypertension suggesting acute PE. Chest computed tomographic angiography (CTA) showed about 6.9 × 6.1 × 9.9 cm sized lobulated giant saccular aneurysm originating from mainly SVC and partially involving left brachiocephalic vein with internal thrombi (). Considerable amounts of thromboembolic filling defects in left pulmonary artery, both left and right lobar, segmental, and subsegmental arteries were also noted (). Three-dimensional reconstruction with endovascular views showed the giant saccular SVC aneurysm with 4.1 × 3.7 cm sized internal thrombi, and the thrombi protruded into the SVC through the narrow aneurysmal neck (). Venous CTA of the lower extremities and abdominal CTA showed no evidence of deep vein thrombosis or other venous aneurysms. To exclude the possible hypercoagulable status as a cause of pulmonary thromboembolism, the laboratory tests for hypercoagulability was done and revealed no abnormalities. Surgical exclusion of SVC aneurysm with pulmonary embolectomy was planned, but the patient and family refused surgery. Therefore, thrombolytic therapy using recombinant tissue plasminogen activator with the dose of 200 mg was administered intravenously for 2 hr for hemodynamically significant PTE, and the RV function and pulmonary artery pressure was normalized on FU echocardiography. However, the patient complained recurrent chest pain and dyspnea on the next day. FU CTA revealed more decreased amounts of thrombi in the left pulmonary artery and its branches, but the amounts of thrombi in the SVC aneurysm, SVC, right pulmonary artery and its branches were increased. Mobilization of thrombi from the SVC aneurysm due to thrombolytic therapy was the possible cause of recurrent PTE, and it was expected that further embolization of thrombi would be fatal to the patient. Therefore, surgical treatment was strongly recommended. Resection of SVC aneurysm and pulmonary artery embolectomy were performed successfully. At surgery, femoral arterial and venous cannulation was done to prepare for accidental rupture of aneurysm during sternotomy. After dissection of the aneurysm, the other venous cannulation at the innominate vein and isolation of the proximal and distal portion of the aneurysm was done. Under cardiopulmonary bypass, aneurysmal wall was opened longitudinally after snaring of proximal and distal portion of the aneurysm and innominate vein. Aenurysm which contained fresh thrombi was thin-walled and had relatively normal venous endothelium grossly (), and the histopathologic examination showed compatible findings of true aneurysm (). Thin-walled aneurysmal wall was completely resected and subsequent reconstruction of the superior vena cava was performed with glutaraldehyde fixed autologuous pericardium that was already harvested. Outer surface of the pericardium was buttressed with Dacron to prevent potential formation of pseudoaneurysm. A transverse arteriotomy was made in the pulmonary trunk to the left main pulmonary artery and another incision was made in the right main pulmonary artery, and the fresh and organized thrombi were gently extracted. Following the successful surgical management, the mediastinal widening on chest radiography was normalized () and the patient was recovered without any postoperative events. The patient was discharged and treated by anticoagulation with warfarin for 6 months to achieve complete resolution of the possible remained pulmonary arterial thrombi.
A 52-year-old man was referred to our hospital for assessment of a suspicious mass that was detected on a chest radiography during a routine health check. He denied symptoms, including chest pain, hoarseness, hemoptysis, cough, dry cough, and dyspnea. He was a nonsmoker and had no exposure to any environmental fumes or dust.\nPhysical examination revealed normal breathing sounds in both lung fields. Laboratory findings were within normal limits. In these examinations, hematology test results and biochemistry test results were within regular levels. Plain chest computed tomography (CT) displayed a circumscribed soft tissue mass that was located in the anterior mediastinum, measuring 2.1 × 1.4 cm (Figure A). Contrast-enhanced CT showed a demarcated soft tissue mass with no calcification and marginal enhancement (Figure B). The lesion was suspected to be a thymoma rather than a vascular neoplasm before surgery.\nAs a diagnosis was not established through imaging, surgery was scheduled. We approached the tumor, which was removed by thymectomy using video-assisted thoracic surgery (VATS) rather than a median sternotomy. The thymectomy was performed in the lateral decubitus position, utilizing a three-port, right-sided VATS approach under general anesthesia administered through a double-lumen endotracheal tube. Three entry ports were made at the third and sixth intercostal spaces of the right posterior axillary, midaxillary, and midclavicular lines. The camera was introduced via trocar through the lower port at the sixth intercostal space of the midaxillary line. The operative procedure involved removal of the entire thymus gland including the anterior mediastinal fat, with careful attention to preservation of the phrenic nerve and control of thymic venous tributaries draining into the left brachiocephalic vein. There was no invasion into adjacent structures. After careful attention to hemostasis, a chest tube was placed to drain the pleural cavity, and the right lung was reinflated under direct vision. Macroscopically, examination of the resected specimen showed an encapsulated tumor measuring 2.2 × 1.2 × 0.8 cm in the thymus that could be palpated as a soft nodule. The cut surface seemed to have some fresh blood and the soft tissue was taupe, and no phlebolith was discerned in the center. Histopathologically, it was diagnosed as a cavernous hemangioma consisting essentially of a large number of dilated vessels with a single layer of endothelial cells with no signs of atypia or mitosis. Most of the channels contained red blood cells in the cavity (Figure ). No tumor tissue was detected at the surgical margin.\nThe postoperative course was ordinary. The patient was discharged 3 days after the operation with no complication. He has been followed up for 8 months without evidence of recurrence.