Superior vena cava syndrome as first presentation of an undifferentiated carcinoma with unknown origin

Abstract

Introduction: The superior vena cava syndrome (SVCS) results from blood flow obstruction of superior vena cava by invasion, extrinsic compression and/or thrombosis. Clinical case: A 55 year old man, with hypertension, heavy smoker and alcohol user (100 g/d) presents at the emergency room with non-productive cough and dyspnea. On admission it is noted plethora, facial edema and jugular engorgement, upper limbs with edema and chest wall collateral circulation. Blood tests showed normocytic and normochromic anemia (10.2 g/dL), leukocytosis (33,000/μL), thrombocytosis (593,000/μL) and elevation of CRP (20.9 mg/dL). Blood gases reveled hypoxemia (44.8 mm Hg). The chest X-ray exhibits widening of the superior mediastinum; chest CT showed bulky mediastinal mass (90 × 80 × 90 mm), which involves the vascular pedicle and leads to extrinsic compression with marked reduction of the diameter of the trachea and a solitary infra-hilar nodule (24 × 26 mm). Bronchoscopy described 90% trachea occupancy by irregular tumor mass with wall destruction. A tracheal prosthesis was placed. The histological diagnosis was a poorly differentiated carcinoma, with areas of differentiation paving stone (with positive staining for CD10, CK5/6, CAM 5.2, p63, hepatocyt, AE1/3). Beta-HCG, alpha-fetal protein and carcinoma-embryonic antigen were negative. Transferred to the intensive care unit (ICU) due to invasive ventilation need. After review by the oncology and cardiothoracic surgery, and considering the stage (T3bNxMx), aggressiveness and severity in the form of presentation, we opted for palliative and comfort measures. He died in ICU, due to disease progression. Conclusions: The combination of clinical data and imaging in this case were crucial for diagnosis. Intrathoracic malignancy is responsible for nearly 60% SVCS cases. SVCS is a form of presentation of a previously undiagnosed tumor in up to 60% of these cases.