Superior vena cava (SVC) syndrome is a clinical entity with signs and symptoms resulting from obstruction of blood flow through the SVC. The resulting obstruction leads to edema in the upper body, including the head, neck, and upper extremities. Clinical signs and symptoms can include plethora, cyanosis, dyspnea, stridor, cough, and hoarseness, as well as more serious complications such as cerebral edema leading to headache, confusion, and coma. Here, we present an interesting case of a 66-year-old female, with a medical history of esophageal cancer in remission and thyroid cancer currently undergoing radiation therapy, who was admitted for facial and upper extremity swelling. The initial impression was of angioedema or an allergic reaction. Imaging studies showed thrombus in the SVC resulting in SVC syndrome. The patient was treated with heparin initially, with a plan for an interventional radiologist to perform catheter-guided thrombolysis. However, the patient became unstable and ended up requiring mechanical ventilation. The patient was eventually discharged on oral anticoagulants. This case was rare as the patient developed SVC syndrome from venous thrombosis in the absence of any external tumor compression or as a result of an intravascular catheter.