Intracardiac Invasive Thymoma Presenting as Superior Vena Cava Syndrome

Case report: Complete resection of invasive thymoma invading the superior vena cava and right atrium under cardiopulmonary bypass support

Here we describe an uncommon case of a 48-year-old male patient with an invasive thymoma invading the superior vena cava, bilateral innominate veins, right internal jugular vein, right subclavian vein, right atrium, azygos vein, and part of the lung tissues. The tumor was resected entirely under cardiopulmonary bypass support, and the venous bypass using a vascular graft was successfully established between the left innominate vein and the right atrium. The postoperative course was uneventful, and the patient was discharged 15 days after surgery without complications.

Thymomas With Intravascular and Intracardiac Growth

Thymomas are derived from the epithelial component of the thymus and constitute the most common tumor of the anterior mediastinum. These neoplasms are considered malignant for their potential for invasion and metastases. Several histopathologic subclassification schemes have been proposed over the years, however, correlation of histotypes with prognosis remains controversial. In contrast, studies invariably have shown that staging and resection status correlate with oncologic behavior and disease outcomes. In this regard, several staging systems have been presented, though transcapsular invasion and degree of involvement of adjacent anatomic structures are common denominators of all schemes. Involvement of the great vessels and heart most commonly results from direct invasion, which may lead to unusual clinical presentations such as superior vena cava syndrome. Moreover, intravascular and intracardiac growth with or without direct mural invasion rarely occurs. We provide an overview of thymomas with intravascular and intracardiac involvement.

Superior Vena Cava Resection in Locally Advanced Thymoma-Surgical and Survival Outcomes

This study was aimed at reporting the surgical management of superior vena cava invasion in patients with locally advanced thymoma and to evaluate surgical and survival outcomes. This is a retrospective analysis of 12 patients operated for superior vena cava resection for locally advanced thymoma over 8 years in a thoracic surgery centre in India. An analysis of peri-operative variables including complications was carried out. The influence of various predictors on survival was assessed by log-rank test. Intra-operatively, superior vena cava (SVC) alone was involved in 3 (25%) cases, SVC with BCV involvement was there in 8 cases (66.7%) and in 1 patient, the SVC involvement extended into the right atrium also. In all cases, the tumour was resected en bloc with the involved part of SVC. Repair with primary closure was sufficient in 2 cases (16.6%) in view of < 1/3rd of circumferential involvement. However, in remaining 10 cases, SVC was replaced with PTFE graft (single graft in 6 cases, Y-graft in 2 cases and twin grafts in 2 cases). No peri-operative deaths. Overall survival (OS) at 1, 3 and 5 years was 100%, 91.6% and 83.3%, respectively. Myasthenia gravis and higher Masaoka stage (IV A) of the disease were poor predictors of survival. Superior vena cava resection and reconstruction is a feasible and oncologically superior option in invasive thymoma with SVC involvement. This challenging surgical procedure should only be attempted by an experienced team of thoracic and cardiac surgeons at high-volume centre to achieve best outcomes.

Invasive thymoma leading to pulmonary artery embolism during operation: A case report

RATIONALE

Invasive thymoma with intraluminal tumor thrombus may cause pulmonary artery thrombus if the tumor thrombus shed off during operation. However, there is no clinical case report focused on such complication.

PATIENT CONCERNS

A 40-year-old woman presented with repeated chest pain.

DIAGNOSIS

Chest computer tomography showed huge mediastinal mass. Postoperative pathology revealed type B2 and B3 thymoma, with B3 as the main type.

INTERVENTIONS

The patient underwent tumor resection through midline sternotomy in our hospital on September 17, 2018. She received emergent pulmonary artery exploration because the tumor thrombus in superior vena cava shed off unexpectedly during operation. Postoperative pulmonary computer tomography angiography showed right pulmonary artery embolism. Then emergent right pulmonary artery embolectomy was performed through lateral thoracic incision on September 29, 2018.

OUTCOMES

The patient recovered well after surgery. D-dimer reduced rapidly and returned to normal 1 month after the second operation.

LESSONS

Intraluminal tumor thrombus in invasive thymoma patients has a risk of shedding off during operation. Prevention strategy should be made beforehand. Pulmonary artery exploration is necessary once happened.

Reconstruction of mediastinal vessels for invasive thymoma: a retrospective analysis of 25 cases

BACKGROUND

Discuss an appropriate strategy for treatment of invasive thymoma invading adjacent great vessels.

METHODS

A retrospective study on 25 patients with invasive thymoma invading neighboring great vessels was performed. The corresponding data including clinical presentation, operation procedure, adjuvant radio-chemotherapy and follow-up were reviewed.

RESULTS

Twenty of 25 (80%) patients with invasive thymoma underwent complete resection of the tumor along with vessel reconstruction. Intraoperatively, different types of operation were conducted, namely, brachiocephalic vein (BCV)-right atrial appendage (RAA) reconstruction in 11 cases, complex vessel reconstruction (more than one graft) in 1 case and superior vena cava (SVC)-SVC reconstruction in the remaining cases. Ringed polytetrafluoroethylene (PTFE) grafts were used for vessel reconstruction. Postoperatively, three cases suffered from pulmonary infection, and three cases had haemothorax, chylothorax and atelectasis, respectively. Two patients died due to acute respiratory distress syndrome within 90 days after the surgery. Within the remaining patients, 11 cases (44%) experienced a relapse and finally 8 (32%) patients died. Compared to R1 resection group, R0 resection group had a better prognosis (Log-rank P=0.0196). The 3- and 5-year survival rates were 79.6% and 59.1%, with median survival time of 84 months.

CONCLUSIONS

Reconstruction of mediastinal vessels for invasive thymoma is a feasible technology method. Radical resection of the tumor with involved neighboring structures is the key to prolong overall survival for patients suffered from invasive thymoma.

Invasive thymoma presenting as classic superior vena cava syndrome: a case of venous spread metastasis

The approach to an intrinsic cause of superior vena cava syndrome (SVCS) is usually difficult but rewarding. We report a case of a middle-aged man who presented with progressive oedema of the upper half of the body, dyspnoea, cough and weight loss for a 1-year duration. He was a non-smoker without prior hospitalisation. Chest radiography showed right-sided pleural effusion with an apparent normal superior mediastinum. Contrast-enhanced CT of the chest revealed a right atrial mass extending and completely obliterating to superior vena cava. The differentials were tuberculosis, invasive fungal granuloma, sarcoidosis, primary vasculitis, chronic venous thrombosis, cardiac sarcoma/lymphoma and metastatic thyroid tumour or thymoma. He underwent transvenous (femoral approach) biopsy of the mass and then cardiothoracic surgery after haemodynamic instability. Pathology showed invasive thymoma type B3. This case highlights the approach to an intrinsic cause of SVCS, a complication of the transvenous approach, and importantly a noble finding of venous spread metastasis.

Recurrence of thymoma in the right atrium arising from the coronary sinus

Invasive thymoma is a malignant tumor of the anterior mediastinum that could have intravenous affinity associated with a high recurrence rate. This report highlights the need of coronary sinus exploration when intraatrial thymoma recurrence is diagnosed. Surgical resection of invaded coronary sinus can be achieved safely with a good result.

Intracaval and intracardiac extension of invasive thymoma complicated by superior and inferior vena cava syndrome

We present a case of an aged male with invasive thymoma that extended into the right atrium and led to superior and inferior vena cava syndrome. The patient initially presented with edema of the face and bilateral lower extremities. Echocardiography revealed a mass within the right atrium. Imaging studies demonstrated an anterior mediastinal tumor that continuously occupied the bilateral brachiocephalic veins, superior vena cava, and right atrium. Pathological diagnosis of the tumor biopsy was highly suspicious of thymoma. Due to the high risk of wide spread of the tumor, treatments including resection of the tumor were impossible. Several days later he died, and an autopsy was performed. The tumor was type B2 thymoma invading bilateral brachiocephalic veins, superior vena cava and right atrium. Multiple tumor emboli within the pulmonary arteries were identified. Direct cause of death was deemed to be tumor strangulation at the tricuspid orifice. In addition to the superior vena cava syndrome, inferior vena cava syndrome including ectasia of the intrahepatic vessels was confirmed along with pericarditis. To our knowledge, this is the first English report of an autopsy case of intracardiac thymoma extension, and a detailed literature review of similar cases is also presented.

Letter to the editor: concomitant off-pump coronary artery bypass grafting and thymectomy

Thymoma in patients with coronary disease is rare.  Although simultaneously performing a cardiac procedure  and thymectomy for patients with combined thymoma and  cardiac disease has been reported, a clear consensus regard- ing the optimal surgical treatment is lacking. Moreover, in  all of the previously reported cases, the surgical intervention  and standard cardiopulmonary bypass were performed simul- taneously. We present the case of a patient who underwent  combined off-pump coronary artery bypass grafting (CABG)  and thymectomy. We show that this combined procedure is  the treatment of choice for patients with a severely ischemic  myocardium and a malignant thymoma.

Surgical management of stage III thymic tumors

Thymic tumors are classified as stage III when they clearly invade the surrounding structures: pericardium, great vessels (superior vena cava, innominate veins, ascending aorta, and main pulmonary artery), lung parenchyma, phrenic nerves, and chest wall. Surgical treatment with or without induction therapy should always aim to complete resection removing en bloc all the involved structures. Also, extended procedures are justified because only R0 resection allows long-term survival.