Superior Vena Cava Syndrome
Summary of Key Points
Etiology
• Superior vena cava (SVC) syndrome is usually due to a neoplastic process, predominantly primary lung carcinoma, with a disproportionate number of patients having small cell histology; non-Hodgkin lymphoma and metastatic tumors are the next most common.
• SVC syndrome can be iatrogenic; it is sometimes seen as a complication of a central venous line or cardiac surgery.
Evaluation
• A chest radiograph typically shows mediastinal widening; a mass is often seen in the region of the SVC.
• Small-dose cavograms can be safely accomplished to define the exact location and routes of collateral flow.
• Computed tomography scanning identifies the mass and collateral flow and is the most helpful study to guide treatment.
• Treatment of an identified mass before histologic diagnosis is rarely justified unless prior diagnosis is established.
• Methods used to define histology are sputum cytology, endobronchial ultrasound with and without bronchoscopy, lymph node biopsy, thoracentesis, percutaneous biopsy, and video-assisted mediastinoscopy or thoracotomy; these techniques are considered quite safe.
Treatment
• Radiation therapy with or without chemotherapy is the preferred treatment in most malignant causes of SVC obstruction, particularly in treatment-sensitive cancers such as small cell lung cancer.
• Chemotherapy would be the initial treatment of choice if a definitive diagnosis of lymphoma has been made.
• The radiation therapy fractionation schedule depends on tumor histology, stage, prognosis, the patient’s general condition, and whether the obstruction is acute or subacute.
• Surgery is usually reserved for select patients with benign causes of obstruction and consists of a bypass procedure.
• Percutaneously placed, self-expanding intravascular wire stents provide an option or adjunct to other procedures in the palliative treatment of patients (usually with malignant disease).
1. A patient presenting with clinical signs and symptoms suggestive of superior vena cava obstruction (SVCO) should:
A Undergo immediate high-dose radiation therapy because SVCO is a medical emergency
B Receive emergency treatment with combined chemoradiation because most of these patients will have lung cancer
C Undergo diagnostic procedures before any treatment is undertaken if he or she is medically stable
D Be admitted to a palliative care ward for supportive measures because cancer manifesting with SCVO is not curable
2. Which of the following symptoms are commonly seen with SCVO?
3. Which of the following is appropriate management for a 28-year-old woman presenting with a 3-week history of increasing facial swelling, dilated chest veins, and night sweats with a computed tomography scan showing a large anterior mediastinal mass obstructing the SVC?
A Urgent surgery to relieve the obstruction and the mass
B A fine-needle aspirate of the anterior mediastinum under ultrasound guidance
C This presentation most likely indicates lymphoma, and multiagent chemotherapy (such as CHOP-R) should be rapidly administered; she will get immediate relief and most likely will be cured
D This presentation most likely indicates lymphoma, but before initiation of treatment, she should undergo a tissue biopsy, preferably to remove an entire lymph node
4. Which of the following statements is most correct?
A Percutaneous stent placement is a risky procedure and should only be performed for patients with benign causes of SVCO.
B Stent placement can provide rapid relief from the symptoms of SVCO but does not treat the underlying cause.
C Stents provide rapid relief of symptoms but are only a temporizing measure because they will quickly occlude and thus need to be replaced frequently.
D Multiple randomized trials have demonstrated the superiority of stents over radiation, and therefore stents should be the standard of care for patients with SVCO.
5. The most common cause of SVCO in the past two decades is:
1. Answer: C. SVCO is no longer considered a medical emergency, and a definitive diagnosis is critical to appropriate treatment.
2. Answer: A. Edema, cough, and shortness of breath are common presenting symptoms for SVCO. Pain, syncope, headache, and stridor are reported but are not common.
3. Answer: D. Because many types of lymphoma exist, a large tumor biopsy, preferably one that includes nodal architecture and sufficient tissue for detailed molecular testing, should be obtained before starting chemotherapy and/or radiation.
4. Answer: B. Percutaneous stents are safe and effective to treat the symptoms of SVCO, particularly facial and upper body edema. They are generally very safe and do not require replacement, but they do not treat the underlying cause of the obstruction and are likely best used in conjunction with definitive management of the cause.
5. Answer: D. Both small cell and non–small cell lung cancer are the leading causes of SVCO. Nonmalignant causes represent only about 5% of the cases.
