Superior Vena Cava Syndrome With Laryngeal Edema Mimicking Drug-Induced Angioedema: Implications for Otolaryngology

A 64-year-old woman presented to our emergency department with dyspnea and face swelling of 2 weeks’ duration, as well as arm swelling for 5 days. The patient is a heavy smoker and had been on an angiotensin converting enzyme inhibitor (ramipril) for 2 months for essential hypertension. Treatment with ramipril was discontinued 10 days before her initial presentation in our emergency department, as the treating general practitioner suspected angioedema. However, the symptoms further progressed despite a course of oral corticosteroids and antihistamines.

Initial examination showed a symmetric facial swelling, a cervical swelling with distended neck veins, and a bilateral arm swelling. Superficial veins and collaterals were seen on the upper chest. The otolaryngologic examination revealed a supraglottic edema as the most likely cause for the dyspnea. Additionally, a suspicious lesion was observed on the right vocal cord, raising the suspicion of early-stage glottic malignancy. A computer tomography (CT) scan of the neck and thorax was performed with intravenous contrast. The CT scan revealed a mediastinal pretracheal mass, compressing and partially obstructing the superior vena cava (SVC; Figure 1).

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Figure 1.

Contrast-enhanced computer tomography images of the thorax in the axial (A) and coronal (B) planes. A, The scan shows a mediastinal pretracheal tumor (referred to as Tm), with direct contact to the ascending aorta (referred to as AA) and markedly compressing the superior vena cava (referred to as SVC). B, The coronal view of the superior vena cava shows a severely narrowed lumen in its middle portion, due to direct compression by the mediastinal tumor. Note the accumulation of the contrast dye above the site of compression, indicating severe venous congestion in the upper venous system.

The mediastinal mass was biopsied through an endobronchial ultrasound transbronchial needle aspiration, revealing a squamous cell carcinoma, rendering this a case of cancer of unknown primary. Panendoscopy and excisional biopsy of the glottic lesion were performed under general anesthesia. The pathology findings revealed an erosive inflammation without signs of laryngeal malignancy. The patient was accordingly immediately started on palliative chemoimmunotherapy, and subsequently underwent SVC stenting. The venous obstruction symptoms subsequently partially resolved, but the disease progressed further until the patient developed bilateral vocal cord paralysis and died a few months later.

Superior vena cava syndrome (SVCS) is a rare clinical phenomenon, characterized by SVC obstruction, usually due to an underlying malignant cause, most commonly lung cancer, lymphomas, or mediastinal metastases from other malignancies. ^{1 -5} In the literature, 3 cases of laryngeal carcinoma have been reported, with metastatic mediastinal adenopathy causing SVCS without synchronous lung malignancy. ^1,4 Although a primary laryngeal malignancy was ruled out in this particular presented case, we recommend a thorough otolaryngologic examination of patients with SVCS, if imaging studies do not reveal another causative primary tumor, especially in heavy smokers.

The occurrence of laryngeal edema and cervicofacial swelling in patients with SVCS may mimic angioedema, especially in patients under treatment with medications that are known to trigger angioedema. Most importantly, dilated veins of the neck and chest should alert the treating physician to the possibility of venous obstruction and warrant a contrast-enhanced CT to rule out SVC obstruction. In those patients, a complete otolaryngologic examination is essential to exclude upper airway obstruction.