Superior vena cava (SVC) obstruction is most commonly caused by? (AIPG 2011)
|B||Small cell lung cancer|
|C||Non-Small cell lung cancer|
Small cell lung cancer. (Ref. Hari-18th ed., pg. 1730)
Superior vena cava syndrome (Ref. Hari-18th ed., Pg 2266)
1). Superior vena cava syndrome (SVCS) is the clinical manifestation of superior vena cava (SVC) obstruction, with severe reduction in venous return from the head, neck, and upper extremities.
a. Lung cancer
b. Metastatic tumors
c. Intravascular devices (e.g., permanent central venous access catheters, pacemaker/defibrillator leads)
Extra Edge: Lung cancer, particularly of small cell and squamous cell histologies, accounts for approximately 85% of all cases of malignant origin. In young adults, malignant lymphoma is a leading cause of SVCS.
3). Other causes include
a. Aortic aneurysm,
b. Thrombosis, and fibrosing mediastinitis from prior irradiation,
e. Beh|et's syndrome.
Signs and symptoms
1). Shortness of breath is the most common symptom, followed by face or arm swelling.
2). Non pulsatile raised JVP.
3). Positive Pemberton's sign.
It is used to demonstrate the presence of latent pressure in the thoracic inlet. The maneuver is achieved by having the patient elevate both arms until they touch the sides of the face. A positive Pemberton's sign is marked by the presence of facial congestion and cyanosis, as well as respiratory distress after approximately one minute
1). Radiation therapy is the primary treatment for SVCS caused by non-small cell lung cancer and other metastatic solid tumors.
2). Chemotherapy is effective when the underlying cancer is small cell carcinoma of the lung, lymphoma, or germ cell tumor.
Special features of various Lung cancer
- Central Location (2/3), - Atelectasis, - Post- obstructive pneumonia,
- May cavitate.
- Usually peripheral, - Found in scars, -Solitary nodule (52%),
- Upper lobe distribution (69%).
- Mediastinal adenopathy, -Hilar mass, -Small or invisible lung nodule,
- High metastatic potential, -Rapid growth.
- May be associated with Hypoglycemia, Cushing's syndrome, Inappropriate secretion of ADH, excessive gonadotropin secretion.
Large cell undifferentiated (10%)
- Large peripheral mass, - Pleural involvement.