A 59-year-old woman presents with generalized facialswelling and dyspnea that has progressed graduallyover the past month. The patient also reports a sensationof pressure in her neck and ears and swelling of the lowereyelids, neck, upper chest, and upper limbs. The bloodvessels on her upper chest are prominent. A dry, irritatingcough has worsened.
Woman With Facial Swelling and Dyspnea
A 59-year-old woman presents with generalized facialswelling and dyspnea that has progressed graduallyover the past month. The patient also reports a sensationof pressure in her neck and ears and swelling of the lowereyelids, neck, upper chest, and upper limbs. The bloodvessels on her upper chest are prominent. A dry, irritatingcough has worsened.The patient denies fever, chills, sweats, hemoptysis,weight change, chest pain, ankle swelling, nausea, vomiting,hematemesis, melena, weakness, headaches, visionchanges, paresis, paresthesias, seizure, syncope, bladderor bowel incontinence, or ataxia. There is no history ofurinary symptoms.
The patient has smoked about a pack of cigarettesa day for the past 30 years, drinks alcohol socially,and takes no medications.
This mildly obese woman is in moderaterespiratory distress. Temperature is 37C (98.6F);heart rate, 77 beats per minute and regular; respirationrate, 18 breaths per minute; blood pressure, 137/86 mmHg. Pulse oximetry, 93% on room air. Thyroid is not palpable.No breast mass or adenopathy is identified. Chest hasnormal contours with symmetric expansion. Decreasedbreath sounds on the right side, with dullness to percussionat the right base. No wheezes or rales. Jugular veinpulse is elevated. Point of maximal impulse is not displaced.Heart sounds are normal; no murmur or gallop.Abdomen has normal contours with no tenderness ororganomegaly. Carotids are equal and palpable. Neurologicexamination is unremarkable.
White blood cell (WBC) count,6600/L, with 68% polymorphonuclear leukocytes, 28%lymphocytes, 4% eosinophils. Hemoglobin, 14.6 g/dL;platelet count, 275,000/μL; erythrocyte sedimentation rate,28 mm/h. Levels of serum sodium, 128 mEq/L; potassium,4 mEq/L; chloride, 90 mEq/L; carbon dioxide, 26 mEq/L.Blood urea nitrogen level, 3 mg/dL; serum creatinine, 0.3 mg/dL. Thyroid-stimulating hormone, 3.4 μIU/mL.Urinalysis is negative for protein, glucose, and WBCs.You order a chest film and CT scan.
What abnormalities are evident on these images, andwhat do you suspect is the cause?
Cancer of the lung
The chest radiograph shows alarge right perihilar density withinfiltrative changes of the right lowerlung.The CT scan shows a largemass in the superior mediastinum,aortal pulmonary window, andright perihilar and subcarinal regions,with encasement of the superiorvena cava (SVC), right pulmonaryartery, lower trachea, and rightmain-stem bronchus. The mass almostcompletely occludes theSVC. A right pleural effusion is alsoevident.In a patient with a long historyof smoking, SVC obstruction, and asuperior mediastinum mass extendingfrom the perihilar to the subcarinalarea, the likely diagnosis is
cancer of the lung, A.
Further testresults included carcinoembryonicantigen, 3.2 ng/mL; cancer antigen(CA) 19-9, 30 U/mL; CA 125, 70 units; alpha fetoprotein,1.7 ng/mL; human chorionic gonadotropin, less than5 mIU/mL; cocci serology, negative. Assays for antineutrophilcytoplasmic antibody (p-ANCA and c-ANCA), purifiedprotein derivative, rheumatoid arthritis factor, and antinuclear antibody are all negative. Urinalysis: sodium,32 mEq/L; osmolality, 396/mOsm. Serum osmolarity,200/mOsm; serum albumin, 3.7 g/dL. Total bilirubin,0.8 mg/dL; alkaline phosphatase, 95 U/L; aspartate aminotransferase,24 U/L; alanine aminotransferase, 30 U/L.A biopsy specimen of the superiormediastinum mass revealedsmall-cell neuroendocrine carcinoma.A radiation oncologist was consulted,and the patient begandaily radiation treatment. Her facialedema improved markedly, andher respiratory distress diminished.Follow-up chemotherapy wasarranged. However, 1 month later,the patient was brought to the emergencydepartment in severe respiratorydistress; she subsequentlydied of cardiopulmonary arrest.
CAUSES OF SVC SYNDROME
SVC syndrome results from:
These mechanisms can coexist. About 75% to 85%of cases of SVC syndrome are caused by malignanttumors.
SVC syndrome typically affects elderly personswith a significant smoking history. However, this disorderis sometimes seen in younger patients who have afamily history of bronchogenic carcinoma or other lungcancers or who have complications of central venouscatheterization.Patients with SVC syndrome usually present withneck and facial swelling, especially around the eyes, aswell as increasing dyspnea, orthopnea, and cough. Othersymptoms can include head, neck, and ear fullness; dysphagia;hoarseness; hemoptysis; nasal congestion; tongueswelling; headache; dizziness; and syncope. Pain in theupper right side of the chest or interscapular area is notuncommon.The characteristic physical findings reflect the underlyingpathologic processes. Obstruction of venous returnfrom the head, neck, and upper extremities results in dilatedneck veins; an increased number and prominence ofanterior chest wall veins; and edema of the face, arms, andchest. Patients with more advanced disease exhibit proptosis,glossal and laryngeal edema, or altered mentalstatus. The clinical picture is more pronounced if the obstructionis located below the azygos vein.
Obstruction of recent onset is likely to be malignantin origin, whereas long-standing obstruction is morelikely to be benign. Primary lung cancer and lymphomaaccount for 94% of cases of SVC syndrome. The risk ofSVC syndrome is greatest in small-cell lung cancer becauseof the tendency of this cancer to develop centrallyrather than peripherally in the airways. Most patientswith SVC syndrome and lymphoma have non-Hodgkinlymphoma.Other causes of SVC syndrome include thymoma,primary mediastinal germ cell neoplasms, breast cancer,fibrosing mediastinitis following primary infection with
tuberculosis, actinomycosis, aspergillosis,blastomycosis, and nocardiosis. SVC syndromemay also be associated with sarcoidosis and postradiationfibrosis.
LABORATORY AND IMAGING STUDIES
Tumor markers can help identify a malignant process.However, because up to 60% of patients with malignancy-related SVC syndrome present without a knowndiagnosis of cancer, tissue biopsy for histologic diagnosisis required. Because malignancy is the most common underlyingdisorder, most patients with SVC syndrome havean abnormal chest radiograph at presentation. Chest CTis the preferred imaging modality once the diagnosis issuspected. Contrast-enhanced CT defines the level and extentof venous blockage, maps collateral pathways ofvenous drainage, and often permits identification of thecause of venous obstruction.
Treatment is directed at control of the underlyingdisease. Radiation therapy is indicated emergently in patientswith SVC syndrome, especially when malignancy issuspected. Subsequently, chemotherapy can be given topatients with cancer. In nonmalignant conditions, such asthrombotic occlusion, thrombolytic therapy with or withoutpercutaneous angioplasty within 5 days of clot formationis useful; intravenous heparin is another option.
The overall prognosis for patients with tumor-associatedSVC syndrome is closely linked to tumor histologyand stage at presentation.
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