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.
A 52-year-old man was admitted to our hospital for mediastinal mass found incidentally in health examination. He had no special disease history or any symptoms. No face or upper extremity edema was found in physical examination. Enhanced chest computer tomography (CT) showed a size of 5.6*4.3 cm mass in anterior mediastinum, which was enhanced in the artery phase (Fig. ), and it had no clear boundary with left innominate vein and SVC. The CT report suggested high possibility of thymoma. Echocardiographic examination did not reveal any abnormality. Thymoma was diagnosed and he received operation in our hospital through median sternotomy on July 2019. During the operation, a dark red and saccular mass was found in anterior mediastinum with slight pulsation. The mass had no clear boundary with left innominate vein and further exploration revealed they were connected with each other. The membrane of the mass seemed to be very thin and easily bled when touched. Left innominate venous aneurysm with part of SVC involved was highly suspected.\nThe venous aneurysm was resected with the proximal and distal end of the left innominate vein blocked (Fig. ). However, the majority of the left innominate vein wall was involved and only a little part of vessel wall was left after the venous aneurysm was resected, which made the reconstruction of the left innominate vein necessary. Because of the misdiagnosis and lack of abundant preoperative preparation, we decided to take pericardium as material for repairment and reconstruction. We first resected the involved part of SVC with it blocked, and repaired it with a small piece of pericardium. The SVC was unblocked immediately after repairment was finished. Then we took a large piece of pericardium and wrapped it around a needle tube, suturing the two sides to make it a tube in shape with the smooth surface inside (Fig. ). The tube was first anastomosed to the distal end of the left innominate vein. Then we blocked the SVC again and opened a small hole in the side wall and anastomosed the other side of the tube with SVC. The reconstructed left innominate vein and SVC seemed patent and firm (Fig. ). Low molecular heparin was used once per day just for routine anticoagulation after surgery. The patient had an uneventful postoperative course and was discharged 6 days after surgery. He did not take anticoagulant drugs after discharge and was satisfied with the treatment therapy. The pathological diagnosis was mediastinal hemangioma. The patient kept in good condition on the last follow up date of December 2019.